TY - JOUR A1 - Climent Terol, Estela A1 - Mondragón, L. A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. A1 - Marcos, M. Dolores A1 - Murguía, J.R. A1 - Amorós, P. A1 - Rurack, Knut A1 - Pérez-Payá, E. T1 - Selektiver, hoch empfindlicher und schneller Nachweis genomischer DNA mit gesteuerten Materialien am Beispiel von Mycoplasma N2 - Mit DNA verschlossene und mit Farbstoff beladene mesoporöse Siliciumdioxid-Nanopartikel wurden zum Nachweis von Mycoplasma bis zu einer Nachweisgrenze von ca. 70 genomischen DNA-Kopien pro µL in real kontaminierten Zellkulturmedien ohne die Hilfe von PCR-Techniken eingesetzt. KW - DNA KW - Gesteuerte Materialien KW - Mesoporöse Träger KW - Mycoplasma KW - Sonden PY - 2013 U6 - https://doi.org/10.1002/ange.201302954 SN - 0044-8249 SN - 0932-2140 SN - 1521-3757 VL - 125 IS - 34 SP - 9106 EP - 9110 PB - Wiley-VCH CY - Weinheim AN - OPUS4-28970 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Mondragón, L. A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. A1 - Marcos, M. Dolores A1 - Murguía, J.R. A1 - Amorós, P. A1 - Rurack, Knut A1 - Pérez-Payá, E. T1 - Selective, highly sensitive, and rapid detection of genomic DNA by using gated materials: Mycoplasma detection N2 - Come and gate it: DNA-capped mesoporous silica nanoparticles loaded with a dye are used to detect the common contaminate Mycoplasma in real contaminated cell-culture media without needing polymerase chain reaction (PCR) techniques, at a detection limit in the range of 70 DNA genome copies µL-1. KW - DNA KW - Gated materials KW - Mesoporous materials KW - Mycoplasma KW - Sensors PY - 2013 U6 - https://doi.org/10.1002/anie.201302954 SN - 1433-7851 SN - 1521-3773 SN - 0570-0833 VL - 52 IS - 34 SP - 8938 EP - 8942 PB - Wiley-VCH CY - Weinheim AN - OPUS4-28976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hecht, Mandy A1 - Climent Terol, Estela A1 - Biyikal, Mustafa A1 - Sancenón, F. A1 - Martínez-Mánez, Ramon A1 - Rurack, Knut T1 - Gated hybrid delivery systems: En route to sensory materials with inherent signal amplification N2 - Hybrid nanoparticles with a large specific surface area are a particularly exciting vehicle for delivery applications. Such highly porous or container-like structures, usually prepared from silica and frequently from gold, can incorporate a large number of chemical substances such as drug and/or indicator molecules. When equipped with a chemically or physically addressable gating function at the openings of the voids, the release of the cargo can be controlled at will. Because many more molecules can be stored as cargo in the pores of the support than there are functional groups as anchoring sites for the gating entities attached to the outer surface (for efficient pore capping), the systems possess inherent features of (signal) amplification. The present article will introduce various design strategies for different types of physical (light, temperature, magnetism) and chemical (pH, metal ions, anion, small organic molecules, enzymes) stimuli in connection with drug and indicator release. We will highlight exciting aspects of combining both features in theranostic applications and will stress which requirements still have to be met by many of the systems to be readily applicable in a sensory context. KW - Delivery systems KW - Hybrid materials KW - Molecular gates KW - Sensing KW - Theranostics KW - Freisetzungssysteme KW - Hybridmaterialien KW - Molekulare Gatter KW - Sensorik KW - Theranostik PY - 2013 U6 - https://doi.org/10.1016/j.ccr.2013.03.020 SN - 0010-8545 VL - 257 IS - 17-18 SP - 2589 EP - 2606 PB - Elsevier CY - Amsterdam AN - OPUS4-28940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Gröninger, Delia A1 - Hecht, Mandy A1 - Walter, Astrid A1 - Martínez-Mánez, Ramon A1 - Weller, Michael G. A1 - Sancenón, F. A1 - Amorós, P. A1 - Rurack, Knut T1 - Selective, sensitive, and rapid analysis with lateral-flow assays based on antibody-gated dye-delivery systems: The example of triacetone triperoxide N2 - Set them free: Brightly fluorescent indicators that are loaded into mesoporous silica nanoparticle carriers, capped with bulky antibodies, are released into the lateral flow of a test strip upon analyte arrival. Integration of the system into a rapid, simple flow test with fluorescence readout is applied for the selective and sensitive determination of the presence of triacetone triperoxide (TATP) as a prototype small-molecule analyte (see figure). KW - Farbstoffe KW - Sprengstoffe KW - Fluoreszenz KW - Immunoassays KW - Mesoporöse Materialien PY - 2013 U6 - https://doi.org/10.1002/chem.201300031 SN - 0947-6539 SN - 1521-3765 VL - 19 IS - 13 SP - 4117 EP - 4122 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-29508 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Garrido, E. A1 - Hernández-Sigüenza, G. A1 - Climent, Estela A1 - Marcos, M. D. A1 - Rurack, Knut A1 - Gaviña, P. A1 - Parra, M. A1 - Sancenón, F. A1 - Martí-Centelles, V. A1 - Martínez-Máñez, R. T1 - Strip-based lateral flow-type indicator displacement assay for γ-hydroxybutyric acid (GHB) detection in beverages N2 - The use of gamma-hydroxybutyric acid (GHB) in drug-facilitated sexual assault has increased due to its availability and high solubility in aqueous solutions and alcoholic beverages, necessitating the development of rapid methods for GHB detection. In this respect, portable testing methods for use in the field, based on lateral flow assays (LFAs) and capable of detecting trace concentrations of target analytes, are particularly attractive and hold enormous potential for the detection of illicit drugs. Using this strategy, here we report a rapid, low cost, easy-to-handle strip-based LFA for GHB analysis employing a smartphone for fluorescence readout. At molecular signalling level, the ensemble is based on a Cu2+ complex with a tetradentate ligand and the fluorescent dye coumarin 343, which indicate GHB through an indicator displacement assay (IDA) in aqueous solution. When incorporated in a LFA-based strip test this system shows a detection limit as low as 0.03 μM for GHB in MES buffer solution and is able to detect GHB at concentrations of 0.1 μM in soft drinks and alcoholic beverages in only 1 min. KW - Indicator displacement assay KW - Gamma-hydroxybutyric acid KW - Lateral flow assay KW - Test strip KW - Fluorescent dyes KW - Smartphone readout PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-564631 SN - 0925-4005 VL - 377 SP - 1 EP - 7 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-56463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Weller, Michael G. A1 - Martínez-Mánez, R. A1 - Rurack, Knut T1 - Immunochemical design of antibody-gated indicator delivery (gAID) systems based on mesoporous silica nanoparticles N2 - In this work, the optimization of the immunochemical response of antibody-gated indicator delivery (gAID) systems prepared with mesoporous silica nanoparticles has been studied along various lines of system tailoring, targeting the peroxide-type explosive TATP as an exemplary analyte. The mechanism of detection of these gAID systems relies on a displacement of an antibody “cap” bound to hapten derivatives anchored to the surface of a porous hybrid material, allowing the indicator cargo stored in the mesopores to escape and massively amplify the analyte-related signal. Since our aim was to obtain gAID systems with the best possible response in terms of sensitivity, selectivity, and assay time, sera obtained from different immunization boosts were screened, the influence of auxiliary reagents was assessed, structural hapten modification (hapten heterology) was investigated, and various indicator dyes and host materials were tested. Considering that highly selective and sensitive immunological responses are best obtained with high-affinity antibodies which, however, could possess rather slow dissociation constants, leading to slow responses, the main challenge was to optimize the immunochemical recognition system for a rapid response while maintaining a high sensitivity and selectivity. The best performance was observed by grafting a slightly mismatching (heterologous) hapten to the surface of the nanoparticles in combination with high-affinity antibodies as “caps”, yielding for the first time gAID nanomaterials for which the response time could be improved from hours to <5 min. The materials showed favorable detection limits in the lower ppb range and discriminated TATP well against H2O2 and other explosives. Further optimization led to straightforward integration of the materials into a lateral flow assay without further treatment or conditioning of the test strips while still guaranteeing remarkably fast overall assay times. KW - Antibody-gated indicator delivery systems KW - Signal amplification KW - Immunochemical response optimization KW - Test strip analysis KW - TATP KW - Explosives detection KW - Heterologous hapten PY - 2022 U6 - https://doi.org/10.1021/acsanm.1c03417 SN - 2574-0970 VL - 5 IS - 1 SP - 626 EP - 641 PB - American Chemical Society CY - Washington, DC AN - OPUS4-54176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hülagü, Deniz A1 - Tobias, Charlie A1 - Climent Terol, Estela A1 - Gojani, Ardian A1 - Rurack, Knut A1 - Hodoroaba, Vasile-Dan T1 - Generalized Analysis Approach of the Profile Roughness by Electron Microscopy with the Example of Hierarchically Grown Polystyrene–Iron Oxide–Silica Core–Shell–Shell Particles N2 - The roughness as a property of core–shell (CS) microparticles plays a key role in their functionality. Quantitative evaluation of the roughness of CS microparticles is, however, a challenging task with approaches using electron microscopy images being scarce and showing pronounced differences in terms of methodology and results. This work presents a generalized method for the reliable roughness determination of nonplanar specimens such as CS particles from electron microscopic images, the method being robust and reproducible with a high accuracy. It involves a self-written software package (Python) that analyzes the recorded images, extracts corresponding data, and calculates the roughness based on the deviation of the identified contour. Images of single particles are taken by a dual mode scanning electron microscopy (SEM) setup which permits imaging of the same field-of-view of the sample with high resolution and surface sensitive in SE InLens mode as well as in transmission mode (TSEM). Herein, a new type of polystyrene core–iron oxide shell–silica shell particles is developed to serve as a set of lower micrometer-sized study objects with different surface roughness; the analysis of their images by the semiautomatic workflow is demonstrating that the particles’ profile roughness can be quantitatively obtained. KW - Core–shell particles KW - Image analysis KW - Nanoparticles KW - Roughness KW - SEM KW - transmission mode PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-542576 SP - 1 EP - 9 PB - Wiley-VCH AN - OPUS4-54257 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Rurack, Knut T1 - Streifenschnelltest mit ppt-Empfindlichkeit durch Kombination von Elektrochemilumineszenz-Detektion mit Aptamer-gesteuerter Indikatorfreisetzung aus mesoporösen Nanopartikeln N2 - Die Kombination aus elektrogenerierter Chemilumineszenz (ECL) und Aptamer-gesteuerter Indikatorfreisetzung (gAID) aus magnetischen mesoporösen Silica-Nanopartikeln, die in mit Poly(ethylenglycol) und N-(3-Triethoxysilylpropyl) diethanolamin funktionalisiertes Glasfaserpapier eingebettet sind, ermöglichte die Entwicklung eines Schnelltests, mit dem sich Penicillin direkt in verdünnter Milch bis auf 50 +/- 9 ppt in <5 min nachweisen lässt. Die kovalente Bindung der Aptamer-Kappe an das Siliciumdioxid-Gerüst ermöglichte den Verschluss der Poren durch nicht-kovalente elektrostatische Wechselwirkungen mit Oberflächen-Aminogruppen. Die Bindung von Penicillin führte zu einer Faltung des Aptamers, wodurch der zuvor in das Material geladene ECL-Reporter Ru(bpy)32+ freigesetzt wurde und nach lateralem Fluss von einer Smartphone-Kamera nach elektrochemischer Anregung mit einer in einen 3D-gedruckten Halter eingesetzten Siebdruckelektrode detektiert wird. Der Ansatz ist einfach, generisch und bietet Vorteile hinsichtlich Empfindlichkeit, Messunsicherheit und Robustheit gegenüber konventioneller Fluoreszenz- oder elektrochemischer Detektion, insbesondere für Point-of-Need-Analysen anspruchsvoller Matrices und Analyten im Ultraspurenbereich. KW - Schnelltests KW - Elektrochemilumineszenz KW - Aptamere KW - Teststreifen KW - Gesteuerte Freisetzung PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-540205 VL - 133 IS - 50 SP - 26491 EP - 26501 PB - Wiley-VCH CY - Weinheim AN - OPUS4-54020 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Costa, Elena A1 - Weller, Michael G. A1 - Rurack, Knut T1 - Antibody-gated dye delivery systems for Type-I pyrethroids detection N2 - Type-I pyrethroids are frequently used for disinfection purposes on airplanes from and to tropical areas. The WHO (Word Health Organization) defines “disinfection” as the procedure whereby health measures are taken to control or kill the insect vectors of human diseases including dengue, yellow fever and malaria.1 Due to this, a new effective and rapid method for pyrethroids analysis directly in the plane is needed. To detect type-I pyrethroids, gated materials are constructed for the purpose of finely tuning the movement of a cargo from voids of a mesoporous inorganic support to a solution, in response to a predefined stimulus.2 Antibodies are bound to specific functional groups grafted on the support’s surface with the two-fold aim of closing the mesopores and working as biological receptors for the target compounds.2 A specific opening mechanism, activated selectively in presence of pyrethroids as analytes, is able to control the release of an indicator dye previously loaded inside the inorganic support. As only few molecules of pyrethroids are necessary to open a pore and release a large amount of dyes, the system shows an intrinsic signal amplification quantified as a fluorescence emission intensity.3 Different mesoporous silica supports (from nano- and microparticles to platelets and short fibers) were synthetized, characterized and functionalized following different capping strategies. In this contribution, we will compare the temporal response behaviour of the optimized gated materials to verify if the respective delivery systems are properly closed and how fast they can be opened in presence of the analytes. Our results indicate that the trends of the kinetics observed in solution show a better control of the closing/opening mechanism when the epitope region of the antibody (around 10 nm) properly fits the pore size of the carriers. Because the incorporation of an antibody-gated dye-delivery system with a conventional test-strip-based lateral-flow assay allows for the detection of analytes down to the ppb level in an easy-to-operate manner and an overall assay time of 2–5 min, which is fast for a biochemical test,3 we carried out first model studies for a lateral flow test assay on membranes, using a smartphone setup for read-out. T2 - XV EUROPT(R)ODE 2021 CY - Online meeting DA - 28.11.2021 KW - Antibody-gated materials KW - Lateral flow assay KW - Pyrethroids detection PY - 2021 AN - OPUS4-53862 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Rurack, Knut A1 - Hecht, Mandy T1 - Loading and Release of Charged and Neutral Fluorescent Dyes into and from Mesoporous Materials: A Key Role for Sensing Applications N2 - The aim of this study is to determine the efficiency of loading and release of several zwitterionic, neutral, anionic and cationic dyes into/from mesoporous nanoparticles to find the optimum loading and release conditions for their application in detection protocols. The loading is carried out for MCM-41 type silica supports suspended in phosphate-buffered saline (PBS) buffer (pH 7.4) or in acetonitrile, involving the dyes (rhodamine B chloride, rhodamine 101 chloride, rhodamine 101 perchlorate, rhodamine 101 inner salt, meso-(4-hydroxyphenyl)-boron–dipyrromethene (BODIPY), sulforhodamine B sodium salt and fluorescein 27). As a general trend, rhodamine-based dyes are loaded with higher efficiency, when compared with BODIPY and fluorescein dyes. Between the rhodamine-based dyes, their charge and the solvent in which the loading process is carried out play important roles for the amount of cargo that can be loaded into the materials. The delivery experiments carried out in PBS buffer at pH 7.4 reveal for all the materials that anionic dyes are more efficiently released compared to their neutral or cationic counterparts. The overall best performance is achieved with the negatively charged sulforhodamine B dye in acetonitrile. This material also shows a high delivery degree in PBS buffer. KW - Mesoporous materials KW - Charged dyes KW - Neutral dyes KW - Dye loading optimisation KW - Dye release PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-522596 UR - https://www.mdpi.com/2072-666X/12/3/249 VL - 12 IS - 3 SP - 249 PB - MDPI AN - OPUS4-52259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Rurack, Knut T1 - Combining electrochemiluminescence detection with aptamer-gated indicator releasing mesoporous nanoparticles enables ppt sensitivity for strip-based rapid tests N2 - The combination of electrogenerated chemiluminescence (ECL) and aptamer-gated indicator delivering (gAID) magnetic mesoporous silica nanoparticles embedded into glass fibre paper functionalised with poly(ethyleneglycol) and N-(3-triethoxysilylpropyl)diethanolamine allowed the development of a rapid test that detects penicillin directly in diluted milk down to 50 ± 9 ppt in <5 min. Covalent attachment of the aptamer ‘cap’ to the silica scaffold enabled pore closure through non-covalent electrostatic interactions with surface amino groups, while binding of penicillin led to a folding-up of the aptamer thus releasing the ECL reporter Ru(bpy)32+ previously loaded into the material and letting it be detected after lateral flow by a smartphone camera upon electrochemical excitation with a screen printed electrode inserted into a 3D-printed holder. The approach is simple, generic and presents advantages with respect to sensitivity, measurement uncertainty and robustness compared with conventional fluorescence or electrochemical detection, especially for point-of-need analyses of challenging matrices and analytes at ultra-trace levels. KW - Electrochemiluminiscence KW - Hybrid materials KW - Signal amplification KW - Test strip analysis KW - Penicillin PY - 2021 U6 - https://doi.org/10.1002/anie.202110744 SN - 1433-7851 SN - 1521-3773 SP - 1 EP - 11 PB - Wiley-VCH CY - Weinheim AN - OPUS4-53447 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Biyikal, Mustafa A1 - Gröninger, Delia A1 - Weller, Michael G. A1 - Martínez-Máñez, Ramón A1 - Rurack, Knut T1 - Fluorescence-based multiplexed detection on single test strips with antibody-gated mesoporous materials N2 - Rapid testing methods for the use directly at a point-of-need are expected to unfold their true potential especially when offering adequate capabilities for the simultaneous measurement of multiple analytes of interest. However, the implementation of multiplexing features while retaining simplicity, performance and portability is one of the prominent challenges in the field. Keeping in mind these challenges, we decided to combine the use of stimuli-responsive materials for small-molecule sensing relying on chemical signal amplification and their incorporation on paper strips for lateral-flow assays in a straightforward manner. Considering the modularity, high sensitivity and selectivity of antibody-gated indicator delivery systems, a multiplexed assay for three small-molecule explosives TATP, TNT and PETN was developed, allowing to detect the analytes simultaneously with a single test strip at lower ppb concentrations in liquid phase in <5 min, using a fluorescence reader or a smartphone for readout. Because of the versatility of the hybrid material and the modularity of the assay architecture, it is obvious that this generic approach should be easily transferable to food or environmental analysis, point-of-care diagnostics and other areas of application in which the rapid screening for multiple parameters from liquid samples without clean-up in a dedicated laboratory is in demand. T2 - 2021 On-line Symposium on Bioluminiscence, Chemiluminiscence and luminescence spectrometry ISLS-ISBC CY - Online meeting DA - 24.06.2021 KW - Multiplexing KW - Hybrid materials KW - Signal amplification KW - Test Strip analysis KW - Explosives PY - 2021 AN - OPUS4-52889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Wan, Wei A1 - Rurack, Knut T1 - Toward Label-Free Optical Multiplexing of Analytes in Indicator Release Lateral Flow Assays via Detection Zones Containing Tailored Capture Materials N2 - The use of macromolecules and materials immobilized in the detection zone of test strips for indicator capture and focusing in label-free lateral flow assays (LFAs) is described, with emphasis on its future use in low number multiplexing. Several materials such as polyelectrolytes, functionalized mesoporous silica micro- and nanoparticles, chemically modified cellulose or glass fibre (GF) membranes and molecularly imprinted polymer gels coated onto membranes were studied in model assays, before the most promising materials were combined with antibody-gated indicator delivering (gAID) sensor materials. Cellulose, nitrocellulose and GF membranes were used as supports and highly fluorescent dyes of different charge states as model indicators. Combination of the best performing capture materials with gAID systems made it possible to distinctly increase the sensitivity and reduce the measurement uncertainty in the LFA testing of pentaerythritol tetranitrate (PETN) in aqueous samples. In addition, dual-plexing of PETN and 2,4,6-trinitrotoluene (TNT) was realized on a single test strip containing two dedicated capture zones. KW - Rapid tests KW - Vor-Ort-Analytik KW - Multiplexing KW - Teststreifen KW - Molecularly imprinted polymers PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-557873 VL - 2 IS - 4 SP - 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-55787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Garrido, E. A1 - Climent Terol, Estela A1 - Marcos, M. D. A1 - Sancenón, F. A1 - Rurack, Knut A1 - Martínez-Máñez, R. T1 - Dualplex lateral flow assay for simultaneous scopolamine and "cannibal drug" detection based on receptor-gated mesoporous nanoparticles N2 - We report herein the design of a strip-based rapid test utilizing bioinspired hybrid nanomaterials for the in situ and at site detection of the drug scopolamine (SCP) using a smartphone for readout, allowing SCP identification in diluted saliva down to 40 nM in less than 15 min. For this purpose, we prepared a nanosensor based on mesoporous silica nanoparticles loaded with a fluorescent reporter (rhodamine B) and functionalized with bethanechol, a potent agonist of recombinant human muscarinic acetylcholine receptor M2 (M2-AChR). M2-AChR interaction with the anchored bethanechol derivative leads to capping of the pores. The sensing mechanism relies on binding of SCP to M2-AChR resulting in pore opening and delivery of the entrapped rhodamine B reporter. Moreover, the material was incorporated into strips for lateral-flow assays coupled to smartphone readout, giving fast response time, good selectivity, and exceptional sensitivity. In an attempt to a mobile analytical test system for law enforcement services, we have also developed a dualplex lateral flow assay for SCP and 3,4-methylenedioxypyrovalerone (MDPV) also known as the so-called “cannibal drug”. KW - Rapid tests KW - Vor-Ort-Analytik KW - Lateral Flow Assays KW - Scopolamine KW - Gesteuerte Freisetzung KW - Cannibal Drug PY - 2022 U6 - https://doi.org/10.1039/d2nr03325a SP - 1 EP - 9 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-55744 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Biyikal, Mustafa A1 - Gawlitza, Kornelia A1 - Dropa, T. A1 - Urban, M. A1 - Costero, A. M. A1 - Martínez-Mánez, Ramon A1 - Rurack, Knut T1 - A rapid and sensitive strip-based quick test for nerve agents Tabun, Sarin, and Soman using BODIPY-modified silica materials N2 - Test strips that in combination with a portable fluorescence reader or digital camera can rapidly and selectively detect chemical warfare agents (CWAs) such as Tabun (GA), Sarin (GB), and Soman (GD) and their simulants in the gas phase have been developed. The strips contain spots of a hybrid indicator material consisting of a fluorescent BODIPY indicator covalently anchored into the channels of mesoporous SBA silica microparticles. The fluorescence quenching response allows the sensitive detection of CWAs in the μg m−3 range in a few seconds. KW - Chemical warfare agents KW - Fluorescence KW - Hybrid sensor materials KW - Nerve gases KW - Test strip analysis PY - 2016 U6 - https://doi.org/10.1002/chem.201601269 SN - 0947-6539 SN - 1521-3765 VL - 22 IS - 32 SP - 11138 EP - 11142 PB - Wiley CY - Online Library AN - OPUS4-37063 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Gröninger, Delia A1 - Hecht, Mandy A1 - Keil, Karin A1 - Rurack, Knut T1 - Sensitive, selective, and rapid analysis based on antibody-gated dye-delivery systems for the detection of explosives T2 - NANOSMAT Conference CY - Dublin, Ireland DA - 2014-09-08 PY - 2014 AN - OPUS4-31353 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Giménez, C. A1 - Climent Terol, Estela A1 - Aznar, E. A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. A1 - Marcos, D. A1 - Amorós, P. A1 - Rurack, Knut T1 - Towards chemical communication between gated nanoparticles N2 - The design of comparatively simple and modularly configurable artificial systems able to communicate through the exchange of chemical messengers is, to the best of our knowledge, an unexplored field. As a proof-of-concept, we present here a family of nanoparticles that have been designed to communicate with one another in a hierarchical manner. The concept involves the use of capped mesoporous silica supports in which the messenger delivered by a first type of gated nanoparticle is used to open a second type of nanoparticle, which delivers another messenger that opens a third group of gated nanoobjects. We believe that the conceptual idea that nanodevices can be designed to communicate with one another may result in novel applications and will boost further advances towards cooperative systems with complex behavior as a result of the communication between simple abiotic individual components. KW - Chemical communication KW - Gated nanoparticles KW - Mesoporous materials KW - Nanoparticles community KW - Nanoparticles PY - 2014 U6 - https://doi.org/10.1002/anie.201405580 SN - 1433-7851 SN - 1521-3773 SN - 0570-0833 VL - 53 IS - 46 SP - 12629 EP - 12633 PB - Wiley-VCH CY - Weinheim AN - OPUS4-32136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Marcos, D. A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. A1 - Soto, J. A1 - Rurack, Knut A1 - Amorós, P. T1 - The determination of methylmercury in real samples using organically capped mesoporous inorganic materials capable of signal amplification KW - Chemosensors KW - Fluorescence KW - Mesoporous materials KW - Methylmercury KW - Methylquecksilber KW - Sensoren KW - Mesoporöse Materialien KW - Fluoreszenz KW - Hybridmaterialien PY - 2009 U6 - https://doi.org/10.1002/anie.200904243 SN - 1433-7851 SN - 1521-3773 SN - 0570-0833 VL - 48 IS - 45 SP - 8519 EP - 8522 PB - Wiley-VCH CY - Weinheim AN - OPUS4-20308 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Hecht, Mandy A1 - Witthuhn, Heike A1 - Jakubowski, Norbert A1 - Rurack, Knut T1 - Trace Hg2+ Sensing and Efficient Hg2+ Scavenging with Hybrid Mesoporous Silica Materials Incorporating Fluorescent Probes N2 - Mercury is a highly toxic, bioaccumulative heavy metal that can cause serious health problems even at low concentrations, thus presenting a major threat for the natural water resources. Its high toxicity entails low MCL values (e.g., 2 ppb),[1] requiring at best materials that cannot only selectively detect Hg2+ at trace levels but also effectively remove it. Various such dual functional materials have been developed in the past.[2] However, most of these approaches have limitations with respect to sensitivity and selectivity, show slow responses or require complex instrumentation. Here we report the development of mesoporous silica materials containing boron-dipyrromethene (BODIPY) probes in their pore systems that allow for the sensitive and selective detection of Hg2+ in water via fluorescence enhancement while at the same time efficiently scavenging the toxic heavy metal. For this purpose, we adopted an earlier strategy[3] and prepared a refined BODIPY probe which was directly adsorbed on the surface of SBA-15-type silica having been functionalized with different organic moieties. Of all the materials tested, SBA-15 expressing propyl chains responded best, allowing for an excellent discrimination against Ag+ and other metals as well as a high sensitivity for Hg2+ with a limit of detection of 1.5 ppb. The performance of the hybrids with regard to sensing and scavenging was validated by ICP-OES measurements before and after exposure of the materials to Hg2+-containing solutions, allowing retentions of 0.07 g Hg2+ g solid-1. Control studies revealed that while the fluorescent probe is responsible for the very sensitive indication at low Hg2+ concentrations, the majority of the toxic metal ion is scavenged at the walls of the silica material. Current work is directed at the incorporation of these sensor particles into filtration systems for monitoring purposes. T2 - 12. Dresdner Sensor-Symposium CY - Dresden, Germany DA - 2015-12-07 PY - 2015 AN - OPUS4-35081 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela T1 - Design and synthesis of lateral flow tests containing antibody-gated materials N2 - Methods for the rapid and sensitive detection of target analytes are gaining importance in medical diagnostics and environmental monitoring, in the security, occupational health and safety as well as food sectors. Among all the methods employed for rapid tests, lateral flow assays (LFAs) are the most commonly used. However, some drawbacks are that most of these tests either indicate the analyte only indirectly, and in other cases the sensitivity is not high enough. Keeping in mind these limitations, the use of stimuli-responsive materials for small-molecule sensing relying on chemical signal amplification and utilizing specific interactions between biomolecules such as antibodies and the corresponding analytes are particularly attractive. Such materials can also be incorporated on paper strips for lateral-flow assays in a straightforward manner. These sensing materials comprise mesoporous silica nanoparticles loaded with indicator molecules and containing certain hapten derivative molecules covalently grafted at the surface, which bind to the respective antibody and inhibit the release of a dye as reporter (Scheme 1). In presence of the designated analyte, a displacement of the antibody from the material is observed, allowing the release of dye. Because a large number of indicator molecules can be released when a single analyte molecule binds to an antibody cap, a strong signal amplification is observed. Considering the modularity, high sensitivity and selectivity of these antibody-gated indicator delivery systems, the presentation discusses general aspects of system design as well as analytical performance and highlights the integration into a lateral-flow assay, showing as an example the determination of the explosives TATP, TNT and PETN with a fluorescence readout, in single-substance and multiplexing modes. T2 - International Webinar on Biosensors and Bioelectronics CY - Online meeting DA - 20.07.2020 KW - Multiplexing detection KW - Rapid testing methods KW - Gated hybrid materials KW - Lateral flow tests KW - Explosives detection PY - 2020 UR - https://europeanmeetings.net/conferences/biosensor-bioelectronics AN - OPUS4-51038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bell, Jérémy A1 - Climent Terol, Estela A1 - Hecht, Mandy A1 - Buurman, Merwe A1 - Rurack, Knut T1 - Combining a droplet-based microfluidic tubing system with gated indicator releasing nanoparticles for mercury trace detection N2 - A droplet-based microfluidic sensor was developed for the detection of Hg2+ traces in water. The approach uses gated mesoporous nanoparticles loaded with a fluorescent BODIPY dye. The squaraine-based gating mechanism is highly selective for Hg2+ and the indicator release mechanism ensures sensitive detection. The microfluidic system is modular and was assembled from simple PTFE/PFA tubes, while detection was realized with standard optomechanic, optic, and electronic parts. The sensor shows a stable response without memory effects and allows the detection of Hg2+ in water down to 20 ppt. KW - Microfluidic sensor KW - Gated delivery system KW - Fluorescence KW - Mercury KW - Hybrid nanoparticles PY - 2016 U6 - https://doi.org/10.1021/acssensors.5b00303 SN - 2379-3694 VL - 1 IS - 4 SP - 334 EP - 338 PB - American Chemical Society CY - Washington, DC AN - OPUS4-35831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Rurack, Knut T1 - Dual detection of the explosives TATP (triacetone triperoxide) and TNT (trinitrotoluene) using antiboby-gated mesoporous silicia materials T2 - Network Meeting of the Alexander von Humboldt Fundation CY - Bremen DA - 2015-04-15 PY - 2015 AN - OPUS4-33540 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Rurack, Knut T1 - Integration of novel specific gated hybrid materials into versatile platforms for advanced sensing applications T2 - Network Meeting of the Alexander von Humboldt Fundation CY - Bremen DA - 2015-04-15 PY - 2015 AN - OPUS4-33541 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Biyikal, Mustafa A1 - Rurack, Knut T1 - Rapid, sensitive and selective determination of nerve agent simulants in the gas phase employing BODIPY-modified silica materials T2 - MAF 14, 14th Conference on methods and applications of fluorescence CY - Würzburg, Germany DA - 2015-09-13 PY - 2015 AN - OPUS4-34659 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Biyikal, Mustafa A1 - Gawlitza, Kornelia A1 - Rurack, Knut T1 - Rapid, sensitive and selective fluorescence sensing device for the determination of the nerve agents Sarin, Soman and Tabun in the gas phase N2 - The organophosphate nerve agents Tabun (GA), Sarin (GB) and Soman (GD) are among the most toxic chemical warfare agents (CWA) known, and exert their biological effects by irreversibly inhibiting acetylcholinesterase enzymes of the human nerve system. The use of these agents in the past century has killed millions of civilians around the world during World Wars I and II, and after that, approximately 40.000 tons of chemical ammunition were dumped into the Baltic Sea, containing ca. 13.000 tons of chemical warfare agents. Since their production, almost all the nations of the world have been strictly avoiding the development and use of CWA, participating in active destruction of CWA stockpiles, especially since the Chemical Weapon Convention (CWC) of 1993. However, CWA have been used in offensive ways against civilian population by terrorists, as for instance in the fatal Tokyo subway terror incident of 1995 or, most recently, against antigovernment demonstrators in Syria in 2013. Due to their higher toxicity and continuous use, it is therefore very important to develop simple and fast detection methods relying on new nerve agent sensing modalities for use in control and inspection. A practically useful fluorescent probe must possess a rapid response and high sensitivity, and shall be implementable into easy-to-use devices for real time detection by untrained personnel. Taking into account this fact, in this work we have synthesized several mesoporous silica materials containing boron–dipyrromethene (BODIPY) moieties for the detection of nerve agents GA, GB and GD in the gas phase. Development of our system indicated that the most potent materials are able to respond to the presence of nerve agent simulants diethyl cyanophosphonate, diethyl chlorophosphate and diisopropyl fluorophosphate, which have to be used in a laboratory setting, yet also for the real nerve agents Sarin, Soman and Tabun, producing a strong quenching of the fluorescence. Furthermore, a portable device for the detection of GA, GB and GD in the gas phase has been prepared for in situ sensing and rapid screening applications, consisting of strips that are able to indicate the targets down to below 1 mgm-3 which is below the LD50 values. T2 - XIII Europtrode Conference CY - Graz, Austria DA - 20.03.2016 KW - nerve agent KW - mesoporous material KW - sensor PY - 2016 AN - OPUS4-35921 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Costa, Elena A1 - Gawlitza, Kornelia A1 - Wan, Wei A1 - Weller, Michael G. A1 - Rurack, Knut T1 - Antibody-gated indicator releasing mesoporous materials: a potential biosensor platform to be used in the development of rapid tests N2 - The urgent necessity to carry out reliable and relevant analytical measurements directly at a point-of-need is one of the current drivers for the development of miniaturised analytical systems, quick tests and wearables. Despite their simplicity, this type of tests must guarantee analytical relevance and reliability like laboratory-based analysis, e.g., in terms of sensitivity, selectivity, immunity against false positives and false negatives as well as robustness and repeatability. Keeping in mind the high sensitivity offered by gated indicator-releasing micro- and nanoparticles due to their inherent features of signal amplification, we performed several optimisations to develop a potential biosensor platform for use in rapid tests. Conceptually, these gated materials are closely related to drug delivery systems, consisting of high porous materials usually closed with macromolecular “caps” and loaded with indicator molecules that are released in presence of a target analyte. However, the key difference between the two types of functional materials is that many drug delivery systems should deliver their cargo over a longer period, often many hours, whereas the gated materials prepared for sensing should show fast release kinetics, on the order of <5 min. With the aim to optimise and adapt gated materials for sensing purposes, we prepared in this work several antibody-gated materials for small-molecule sensing. The materials consisted of porous silica particles containing indicator molecules in the pores and certain hapten molecules grafted to the particle surface close to the pore openings. The pores were then capped with antibodies binding to these haptens, thus inhibiting the escape of the indicators from inside of the pores. In presence of the corresponding analyte, the antibody is displaced from the surface of the material, allowing the escape of the indicators. This allows the detection of the analyte indirectly through an inherent signal amplification. In this work, the insecticide permethrin, a type-I pyrethroid, was selected as target model, because type-I pyrethroids play an important role in airplane disinfection. A first in-depth study of the various chemical tuning options of such antibody gated systems was performed. Different mesoporous silica supports, different functionalisation routes and different loading sequences were assessed. The materials’ performances were evaluated by studying their temporal response behaviour and detection sensitivity, including the tightness of pore closure (through the amount of blank release in absence of analyte) and the release kinetics. Our results indicate that the better the paratope-accommodating Fab region of the antibody “cap” fits into the host material’s pore openings, the better the closing/opening mechanism can be controlled. Because such materials can be used in various different formats from suspension assays[1] via microfluidic chips[2] to test strip-based lateral flow assays,[3] such materials present a powerful analytical particle platform for the sensitive analytics and diagnostics outside of a laboratory, realising sensitivities down to the µg kg–1 range in less analysis times of less than 5 min as we have recently demonstrated.[4] T2 - Biosensors for Pandemics CY - Online conference DA - 06.05.2020 KW - Hybrid materials KW - Pyrethroids KW - Signal amplification PY - 2020 UR - http://www.confstreaming.com/Biosensors2020/ AN - OPUS4-50744 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Costa, Elena A1 - Gawlitza, Kornelia A1 - Wan, Wei A1 - Weller, Michael G. A1 - Rurack, Knut T1 - Antibody-gated indicator releasing mesoporous materials: a potential biosensor platform to be used in the development of rapid tests N2 - The urgent necessity to carry out reliable and relevant analytical measurements directly at a point-of-need is one of the current drivers for the development of miniaturised analytical systems, quick tests and wearables. Despite their simplicity, this type of tests must guarantee analytical relevance and reliability like laboratory-based analysis, e.g., in terms of sensitivity, selectivity, immunity against false positives and false negatives as well as robustness and repeatability. Keeping in mind the high sensitivity offered by gated indicator-releasing micro- and nanoparticles due to their inherent features of signal amplification, we performed several optimisations to develop a potential biosensor platform for use in rapid tests. Conceptually, these gated materials are closely related to drug delivery systems, consisting of high porous materials usually closed with macromolecular “caps” and loaded with indicator molecules that are released in presence of a target analyte. However, the key difference between the two types of functional materials is that many drug delivery systems should deliver their cargo over a longer period, often many hours, whereas the gated materials prepared for sensing should show fast release kinetics, on the order of <5 min. With the aim to optimise and adapt gated materials for sensing purposes, we prepared in this work several antibody-gated materials for small-molecule sensing. The materials consisted of porous silica particles containing indicator molecules in the pores and certain hapten molecules grafted to the particle surface close to the pore openings. The pores were then capped with antibodies binding to these haptens, thus inhibiting the escape of the indicators from inside of the pores. In presence of the corresponding analyte, the antibody is displaced from the surface of the material, allowing the escape of the indicators. This allows the detection of the analyte indirectly through an inherent signal amplification. In this work, the insecticide permethrin, a type-I pyrethroid, was selected as target model, because type-I pyrethroids play an important role in airplane disinfection. A first in-depth study of the various chemical tuning options of such antibody gated systems was performed. Different mesoporous silica supports, different functionalisation routes and different loading sequences were assessed. The materials’ performances were evaluated by studying their temporal response behaviour and detection sensitivity, including the tightness of pore closure (through the amount of blank release in absence of analyte) and the release kinetics. Our results indicate that the better the paratope-accommodating Fab region of the antibody “cap” fits into the host material’s pore openings, the better the closing/opening mechanism can be controlled. Because such materials can be used in various different formats from suspension assays[1] via microfluidic chips[2] to test strip-based lateral flow assays,[3] such materials present a powerful analytical particle platform for the sensitive analytics and diagnostics outside of a laboratory, realising sensitivities down to the µg kg–1 range in less analysis times of less than 5 min as we have recently demonstrated.[4] T2 - Biosensors for Pandemics CY - Online conference DA - 06.05.2020 KW - Hybrid materials KW - Pyrethroids KW - Signal amplification PY - 2020 UR - http://www.confstreaming.com/Biosensors2020/ AN - OPUS4-50746 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Costa, Elena A1 - Climent Terol, Estela A1 - Ast, S. A1 - Weller, Michael G. A1 - Canning, J. A1 - Rurack, Knut T1 - Development of a lateral flow test for rapid pyrethroid detection using antibody-gated indicator-releasing hybrid materials N2 - The employment of type-I pyrethroids for airplane disinfection in recent years underlines the necessity to develop sensing schemes for the rapid detection of these pesticides directly at the point-of-use. Antibody-gated indicator-releasing materials were thus developed and implemented with test strips for lateral-flow assay-based analysis employing a smartphone for readout. Besides a proper matching of pore sizes and gating macromolecules, the functionalization of both the material's outer surface as well as the strips with PEG chains enhanced system performance. This simple assay allowed for the detection of permethrin as a target molecule at concentrations down to the lower ppb level in less than 5 minutes. KW - Lateral flow test KW - Gated hybrid material KW - Fluorescence KW - Smartphone readout device KW - Pyrethroid KW - Pesticide KW - Insecticide KW - SBA-15 KW - Permethrin PY - 2020 U6 - https://doi.org/10.1039/d0an00319k SN - 0003-2654 SN - 1364-5528 VL - 145 IS - 10 SP - 3490 EP - 3494 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-50756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Biyikal, Mustafa A1 - Gröninger, Delia A1 - Weller, Michael G. A1 - Martínez Mánez, R. A1 - Rurack, Knut ED - Climent Terol, Estela T1 - Multiplexed Detection of Analytes on Single Test Strips with Antibody-Gated Indicator-Releasing Mesoporous Nanoparticles N2 - Rapid testing methods for the use directly at apointof need are expected to unfold their true potential especiallywhen offering adequate capabilities for the simultaneousmeasurement of multiple analytes of interest. Considering theunique modularity,high sensitivity,and selectivity of antibody-gated indicator delivery (gAID) systems,amultiplexed assayfor three small-molecule explosives (TATP, TNT,PETN) wasthus developed, allowing to detect the analytes simultaneouslywith asingle test strip at lower ppb concentrations in the liquidphase in < 5min using afluorescence reader or asmartphonefor readout. While the TNT and PETN systems were newlydeveloped here,all the three systems also tolerated harshermatrices than buffered aqueous model solutions.Besidesasingle-track strip,the outstanding modularity of the hybridbiosensor materials in combination with strip-patterningtechnologies allowed us to obtain amultichannel strip inastraightforwardmanner,offering comparable analyticalperformance while allowing to be tailored even more to theusersneed. KW - Multiplexing KW - Explosives detection KW - Gated materials KW - Fluorescence PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-518424 SN - 1433-7851 SN - 1521-3773 VL - 59 IS - 52 SP - 23862 EP - 23869 PB - Wiley-VCH CY - Weinheim AN - OPUS4-51842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Biyikal, Mustafa A1 - Gröninger, Delia A1 - Weller, Michael G. A1 - Martínez Mánez, R. A1 - Rurack, Knut T1 - Multiplex‐Nachweis von Analyten auf einem einzelnen Teststreifen mit Antikörper‐gesteuerten und Indikator freisetzenden mesoporösen Nanopartikeln N2 - Vor dem Hintergrund der einzigartigen Modularität, hohen Empfindlichkeit und Selektivität von Antikörper‐gesteuerten Indikatorfreisetzungssystemen (gAID‐Systemen) wurde hier ein Multiplex‐Assay für drei organische Explosivstoffmoleküle (TATP, TNT, PETN) entwickelt, der es erlaubt, die Analyten gleichzeitig in flüssiger Phase mit einem einzelnen Teststreifen und einem Fluoreszenzlesegerät bzw. Smartphone als Detektor in Konzentrationen bis in den unteren ppb‐Bereich in <5 min nachzuweisen. Alle drei Systeme, darunter die hier neu entwickelten Systeme für TNT und PETN, tolerieren zudem nicht nur gepufferte wässrige Modelllösungen, sondern auch komplexere Matrices. Neben einem konventionellen Teststreifen mit einem Kanal erlaubte uns die Anwendung von Wachsdrucktechnologie das Herstellen von mehrkanaligen Streifen mit vergleichbarer analytischer Leistungsfähigkeit, was das enorme Potenzial der modular aufgebauten, hybriden Biosensormaterialien im Hinblick auf eine für den Endanwender maßgeschneiderte Vor‐Ort‐Analytik unterstreicht. KW - Multiplex KW - Gesteuerten Nanopartikeln KW - Explosiven PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-518431 SN - 1521-3757 SN - 0044-8249 VL - 132 IS - 52 SP - 24071 EP - 24078 PB - Wiley-VCH CY - Weinheim AN - OPUS4-51843 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Costa, Elena A1 - Climent Terol, Estela A1 - Gawlitza, Kornelia A1 - Wan, Wei A1 - Weller, Michael G. A1 - Rurack, Knut T1 - Optimization of analytical assay performance of antibody-gated indicator-releasing mesoporous silica particles N2 - Antibody-gated indicator delivery (gAID) systems based on mesoporous silica nano- and microparticle scaffolds are a promising class of materials for the sensitive chemical detection of small-molecule analytes in simple test formats such as lateral flow assays (LFAs) or microfluidic chips. Their architecture is reminiscent of drug delivery systems, only that reporter molecules instead of drugs are stored in the voids of a porous host particle. In addition, the pores are closed with macromolecular “caps” through a tailored “gatekeeping” recognition chemistry so that the caps are opened when an analyte has reacted with a “gatekeeper”. The subsequent uncapping leads to a release of a large number of indicator molecules, endowing the system with signal amplification features. Particular benefits of such systems are their modularity and adaptability. With the example of the immunochemical detection of type-I pyrethroids by fluorescent dye-releasing gAID systems, the influence of several tuning modes on the optimisation of such hybrid sensory materials is introduced here. In particular, different mesoporous silica supports (from nano- and microparticles to platelets and short fibres), different functionalisation routes and different loading sequences were assessed. The materials’ performances were evaluated by studying their temporal response behaviour and detection sensitivity, including the tightness of pore closure (through the amount of blank release in the absence of analyte) and the release kinetics. Our results indicate that the better the paratope-accommodating Fab region of the antibody “cap” fits into the host material's pore opening, the better the closing/opening mechanism can be controlled. Because such materials are well-suited for LFAs, performance assessment included a test-strip format besides conventional assays in suspension. In combination with dyes as indicators and smartphones for read-out, simple analytical tests for use by untrained personnel directly at a point-of-need such as an aeroplane cabin can be devised, allowing for sensitivities down to the μg kg−1 range in <5 min with case-required selectivities. KW - Antibody-gated indicator delivery KW - Lateral flow assay KW - SBA-15 KW - SBA-16 KW - Type-I pyrethroids KW - Phenothrin KW - Permethrin KW - Etofenprox KW - Amplification KW - Biosensors KW - Immunoassays KW - Mesoporous particles KW - Optical detection PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-517053 VL - 8 IS - 22 SP - 4950 EP - 4961 PB - Royal Society of Chemistry AN - OPUS4-51705 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tobias, Charlie A1 - Climent Terol, Estela A1 - Gawlitza, Kornelia A1 - Rurack, Knut T1 - Polystyrene Microparticles with Convergently Grown Mesoporous Silica Shells as a Promising Tool for Multiplexed Bioanalytical Assays N2 - Functional core/shell particles are highly sought after in analytical chemistry, especially in methods suitable for single-particle analysis such as flow cytometry because they allow for facile multiplexed detection of several analytes in a single run. Aiming to develop a powerful bead platform of which the core particle can be doped in a straightforward manner while the shell offers the highest possible sensitivity when functionalized with (bio)chemical binders, polystyrene particles were coated with different kinds of mesoporous silica shells in a convergent growth approach. Mesoporous shells allow us to obtain distinctly higher surface areas in comparison with conventional nonporous shells. While assessing the potential of narrow- as well as wide-pore silicas such as Mobil composition of matter no. 41 (MCM-41) and Santa Barbara amorphous material no. 15 (SBA-15), especially the synthesis of the latter shells that are much more suitable for biomolecule anchoring was optimized by altering the pH and both, the amount and type of the mediator salt. Our studies showed that the best performing material resulted from a synthesis using neutral conditions and MgSO4 as an ionic mediator. The analytical potential of the particles was investigated in flow cytometric DNA assays after their respective functionalization for individual and multiplexed detection of short oligonucleotide strands. These experiments revealed that a two-step modification of the silica surface with amino silane and succinic anhydride prior to coupling of an amino-terminated capture DNA (c-DNA) strand is superior to coupling carboxylic acid-terminated c-DNA to aminated core/shell particles, yielding limits of detection (LOD) down to 5 pM for a hybridization assay, using labeled complementary single-stranded target DNA (t-DNA) 15mers. The potential of the use of the particles in multiplexed analysis was shown with the aid of dye-doped core particles carrying a respective SBA-15 shell. Characteristic genomic sequences of human papillomaviruses (HPV) were chosen as the t-DNA analytes here, since their high relevance as carcinogens and the high number of different pathogens is a relevant model case. The title particles showed a promising performance and allowed us to unequivocally detect the different high- and low-risk HPV types in a single experimental run. KW - Bead-based assay KW - Core-shell particles KW - Human papillomavirus KW - Mesoporous silica KW - Multiplexing PY - 2020 U6 - https://doi.org/10.1021/acsami.0c17940 SN - 1944-8244 VL - 13 IS - 1 SP - 207 EP - 218 PB - American Chemical Society CY - Washington, DC AN - OPUS4-51955 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Gotor, Raul A1 - Tobias, Charlie A1 - Bell, Jérémy A1 - Martin-Sanchez, Pedro A1 - Rurack, Knut T1 - Dip Sticks Embedding Molecular Beacon-Functionalized Core−Mesoporous Shell Particles for the Rapid On-Site Detection of Microbiological Fuel Contamination N2 - Microbial contamination of fuels by fungi and bacteria presents risks of corrosion and fuel system fouling. In this work, a rapid test for the determination of microbial genomic DNA from aqueous fuel extracts is presented. It combines test strips coated with polystyrene core/mesoporous silica shell particles, to the surface of which modified fluorescent molecular beacons are covalently grafted, with a smartphone detection system. In the hairpin loop, the beacons incorporate a target sequence highly conserved in all bacteria, corresponding to a fragment of the 16S ribosomal RNA gene, which is also present to a significant extent in the 18S rRNA gene of fungi, allowing for broadband microbial detection. In the developed assay, the presence of genomic DNA extracts from bacteria and fungi down to ca. 20−50 μg L−1 induced a distinct fluorescence response. The optical read-out was adapted for on-site monitoring by combining a 3D-printed case with a conventional smartphone, taking advantage of the sensitivity of contemporary complementary metal oxide semiconductor (CMOS) detectors. Such an embedded assembly allowed to detect microbial genomic DNA in aqueous extracts down to ca. 0.2−0.7 mg L−1 and presents an important step toward the on-site uncovering of fuel contamination in a rapid and simple fashion. KW - Bacteria KW - Fungi KW - Rapid test KW - Fluorescence KW - Smartphone KW - Biofouling PY - 2020 U6 - https://doi.org/10.1021/acssensors.0c01178 SN - 2379-3694 VL - 6 IS - 1 SP - 27 EP - 34 PB - American Chemical Society CY - Washington, DC AN - OPUS4-51956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Biyikal, Mustafa A1 - Gawlitza, Kornelia A1 - Dropa, T. A1 - Urban, M. A1 - Costero, A. M. A1 - Martínez-Mánez, Ramon A1 - Rurack, Knut T1 - Determination of the chemical warfare agents Sarin, Soman and Tabun in natural waters employing fluorescent hybrid silica materials N2 - A novel mesoporous silica material containing boron–dipyrromethene (BODIPY) moieties (I) is employed for the detection of nerve agent simulants (NASs) and the organophosphate nerve or chemical warfare agents (CWAs) Sarin (GB), Soman (GD), and Tabun (GA) in aqueous environments. The reactive BODIPY dye with an optimum positioned hydroxyl group undergoes acylation reactions with phosph(on)ate substrates, yielding a bicyclic ring. Due to aggregation of the dyes in water, the sensitivity of the free dye in solution is very low. Only after immobilization of the BODIPY moieties into the silica substrates is aggregation inhibited and a sensitive determination of the NASs diethyl cyanophosphonate (DCNP), diethyl chlorophosphate (DCP) and diisopropyl fluorophosphate (DFP) possible. The signaling mode is a strong quenching of the fluorescence, reaching LODs in the pM range. The best performing hybrid material was singled out from a library of hybrid silicas varying in morphology and surface functionalization. The response to actual CWAs such as GB, GD, and GA has also been tested, offering similar behavior as for the simulants. The proposed reaction mechanism has been verified by investigation of other model materials, containing for instance BODIPY moieties without an optimum hydroxyl group (III) or a BODIPY dye with an all-aliphatic counterpart (IV). The latter can only form a monocyclic reaction product, showing much less reactivity as I. Assays with other possible competitors have been additionally carried out, showing favorably low cross-reactivities. Finally, the determination of NASs in several natural waters has been demonstrated. KW - Nerve agent simulants KW - Mesoporous silica materials KW - Fluorescence detection PY - 2017 UR - http://www.sciencedirect.com/science/article/pii/S0925400517303428 U6 - https://doi.org/10.1016/j.snb.2017.02.115 SN - 0925-4005 VL - 246 SP - 1056 EP - 1065 PB - Elsevier B.V. AN - OPUS4-39739 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Hecht, Mandy A1 - Witthuhn, Heike A1 - Gawlitza, Kornelia A1 - Rurack, Knut T1 - Cover profile for the article "Mix‐&‐read determination of Mercury(II) at trace levels with hybrid mesoporous silica materials incorporating fluorescent probes by a simple mix‐&‐load technique" N2 - Invited for this month’s cover picture is the group of Dr. Knut Rurack at the Department of Analytical Chemistry; Reference Materials at the Bundesanstalt fuer Materialforschung und -pruefung (BAM) in Berlin (Germany). The cover picture shows how differences in color and fluorescence on a test strip can be easily read out with a mobile device. Two reference spots Frame the sensitive spot that indicates the presence of trace amounts of HgII below the threshold in a natural water sample. This dipstick contains a hybrid material that combines boron-dipyrromethene (BODIPY) probes sterically loaded into specifically tailored mesoporous silica particles, allowing for ultrasensitive HgII detection through enhanced fluorescence in a few seconds. The applicability in real water samples and fish extracts are also studied. KW - Mercury KW - Fluorescence KW - Dip-stick assay KW - Group profile PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-471267 SN - 2191-1363 VL - 7 IS - 12 SP - 932 EP - 933 PB - Wiley-VCH CY - Weinheim AN - OPUS4-47126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sarma, Dominik A1 - Carl, Peter A1 - Climent Terol, Estela A1 - Schneider, Rudolf A1 - Rurack, Knut T1 - Multifunctional polystyrene core/silica shell microparticles with antifouling properties for bead-based multiplexed and quantitative analysis N2 - Commercial bead-based assays are commonly built upon polystyrene particles. The polymeric carrier can be encoded with organic dyes and has ideal material properties for cytometric applications such as low density and high refractive index. However, functional groups are conventionally integrated during polymerization and subsequent modification is limited to the reactivity of those groups. Additionally, polystyrene as the core material leads to many hydrophobic areas still being present on the beads’ surfaces even after functionalization, Rendering the particles prone to nonspecific adsorption during an application. The latter calls for several washing steps and the use of additives in (bio)analytical assays. In this contribution, we show how these limitations can be overcome by using monodisperse polystyrene (PS) core/silica (SiO2) shell particles (SiO2@PS). Two different hydrophobic BODIPY (boron−dipyrromethene) dyes were encapsulated inside a poly(vinylpyrrolidone) (PVP) -stabilized polystyrene core in different concentrations to create 5-plex arrays in two separate detection channels of a cytometer. A subsequent modification of the silica shell with an equimolar APTES/PEGS (aminopropyltriethoxysilane/polyethylene glycol silane) blend added multifunctional properties to the hybrid core/Shell microparticles in a single step: APTES provides amino groups for the attachment of a caffeine derivative (as a hapten) to create antigen-coupled microspheres; the PEG moiety effectively suppresses nonspecific binding of antibodies, endowing the surface with antifouling properties. The particles were applied in a competitive fluorescence immunoassay in suspension, and a highly selective wash-free assay for the detection of caffeine in beverages was developed as a proof of concept. KW - Core−shell particles KW - Bead-based assay KW - Multiplex KW - Antifouling surface KW - Mixed surface PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-472931 UR - https://pubs.acs.org/doi/10.1021/acsami.8b10306 SN - 1944-8244 VL - 11 IS - 1 SP - 1321 EP - 1334 PB - American Chemical Society CY - Online Library AN - OPUS4-47293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Hecht, Mandy A1 - Witthuhn, Heike A1 - Gawlitza, Kornelia A1 - Rurack, Knut T1 - Mix‐&‐read determination of Mercury(II) at trace levels with hybrid mesoporous silica materials incorporating fluorescent probes by a simple mix‐&‐load technique N2 - The synthesis, characterization, and application of mesoporous materials containing boron–dipyrromethene (BODIPY) moieties that allow the sensitive and selective detection of HgII in aqueous environments by fluorescence enhancement is reported. For this purpose, BODIPY dye I containing a thia‐aza crown ether receptor as the fluorescent probe for the detection of HgII in aqueous environments is encapsulated into mesoporous materials to avoid self‐quenching or aggregation in water. Determination of HgII is accomplished within a few seconds with high selectivity and sensitivity, reaching a limit of detection of 12 ppt. The determination of trace amounts of HgII in natural waters and in fish extracts is demonstrated by using our sensing material. The incorporation of the material into several μ‐PAD strips yields a portable, cheap, quick, and easy‐to‐handle tool for trace HgII analysis in water. KW - Dyes/pigments KW - Test strips KW - Mesoporous materials KW - Mercury KW - Fluorescence PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-460138 SN - 2191-1363 VL - 7 IS - 12 SP - 957 EP - 968 PB - Wiley-VCH CY - Weinheim AN - OPUS4-46013 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent Terol, Estela A1 - Wan, Wei A1 - Weller, Michael G. A1 - Rurack, Knut T1 - Novel specific bio-gated hybrid materials and their integration into versatile platforms for advanced sensing applications N2 - Methods for the rapid and sensitive detection of target analytes are gaining importance in medical diagnostics and environmental monitoring, in the security, occupational health and safety as well as food sectors. Among all of the methods employed for rapid tests, lateral flow assays (LFAs) are the most commonly used, and hundreds of test kits based on this technique are available on the market. A major drawback is that most of these capture agents either indicate the analyte only indirectly, and in most cases a second binding agent able to bind directly or indirectly to the analytes is necessary (e.g., a secondary labeled antibody). Furthermore, in certain cases in which the (ultra)trace detection of an analyte is required, the traditional approach of a certain number of probe molecules being conjugated to a particular support is not sufficient. Therefore, novel concepts implementing steps of effective signal amplification are urgently required. Keeping in mind these limitations, we thought that the sensitivity of these systems should be improvable through employment of gated reporter molecule-releasing hybrid nanoparticle materials on novel lateral flow devices. On one hand, the gated sensor material can produce a massive signal amplification, by releasing many reporter molecules only after chemical recognition of a few analyte molecules has taken place in an independent and separate step at the pore openings. On the other hand, the employment of tailored capture materials for the selective interaction with the released reporter molecules in a second arbitrary zone on the strip allows to concentrate or focus the latter for more efficient detection or to create selective multi-spot detection zones, which renders the simultaneous detection of several reporter molecules at the same time in multiplexed detection of various analytes possible. For that purpose, we have prepared several stimuli-responsive materials for small-molecule sensing based on specific interactions between biomolecules such as antibodies with the corresponding analytes for the detection of certain explosives. In order to prepare these bio-capped materials, we have selected silica mesoporous nanoparticles (MSNs) as inorganic support due to their unique properties such as defined void structure, high inner surface area and flexible functionalization chemistry. These MSNs are loaded with a brightly fluorescent indicator dye, and the external surface is subsequently functionalized with suitable molecules able to interact with antibodies, efficiently inhibiting dye release. The opening protocol and delivery of the entrapped dye is reminiscent of a displacement reaction involving the presence of the target analyte, producing a displacement of the biomolecule and allowing the detection of the target analyte. The presentation discusses general aspects of system design as well as analytical performance and highlights the integration into a lateral-flow assay, showing as an example the determination of the explosives TATP, TNT and PETN with fluorescence readout, in single-substance and multiplexing modes. T2 - EBS 2019 CY - Florence, Italy DA - 18.02.2019 KW - Bio-gated hybrid materials KW - Signal amplification KW - Explosives determination KW - Fluorescence KW - Rapid test KW - Dip-stick assay PY - 2019 AN - OPUS4-47920 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kubheka, G. A1 - Climent, Estela A1 - Tobias, Charlie A1 - Rurack, Knut A1 - Mack, J. A1 - Nyokong, T. T1 - Multiplexed Detection of Human Papillomavirus Based on AzaBODIPY-Doped Silica-Coated Polystyrene Microparticles N2 - Human papillomavirus (HPV) DNA detection can enable the early diagnosis of high-risk HPV types responsible for cervical cancer. HPV detection is also essential for investigating the clinical behavior and epidemiology of particular HPV types, characterization of study populations in HPV vaccination trials and monitoring the efficacy of HPV vaccines. In this study, two azaBODIPY dyes (1 and 2) were used as references and were doped into polystyrene particles (PS40), while a short HPV DNA single strand was used as a target molecule and was covalently bound to the silica shell. These particles were employed as optical probes in 1:1 hybridization assays, and their potential applicability as a tool for multiplex assays for the detection of different strands of HPV was evaluated using flow cytometry. A good separation in the fluorescence of the four different voncentrations prepared for each dye was observed. To perform the hybridization assays, HPV18, HPV16, HPV11 and HPV6 single strands were attached to the particles through EDC-mediated coupling. The c-DNA-1-PS40 and c-DNA-2-PS40 particles exhibited low limit of detection (LOD) and quantification (LOQ) values for HPV11, and a narrow detection range was obtained. Multiplexed assay experiments were successfully performed for both particles, and the results proved that c-DNA-1-PS40 could potentially be used as a tool for multiplexing assays and merits further in-depth study in this context. KW - Flow cytometry KW - BODIPY dyes KW - Core-shell particles KW - Multiplexed assay KW - Human papillomavirus PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-567358 SN - 2227-9040 VL - 11 IS - 1 SP - 1 EP - 21 PB - MDPI CY - Basel AN - OPUS4-56735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bell, Jérémy A1 - Climent, Estela A1 - Gotor, Raúl A1 - Tobias, Charlie A1 - Martin-Sanchez, Pedro M. A1 - Rurack, Knut T1 - Dipstick coated with polystyrene-silica core-shell particles for the detection of microbiological fuel contamination N2 - Microbial contamination of fuels by fungi or bacteria poses risks such as corrosion and fuel system fouling, which can lead to critical problems in refineries and distribution systems and has a significant economic impact at every stage of the process. Many factors have been cited as being responsible for microbial growth, like the presence of water in the storage tanks. In fact, only 1 % water in a storage system is sufficient for the growth of microorganisms like bacteria or yeasts, as well as for the development of fungal biomass at the oil/water interface. This work presents a rapid test for the accurate determination of genomic DNA from aqueous fuel extracts. The detection is based on the use of polystyrene-mesoporous silica core-shell particles onto which modified fluorescent molecular beacons are covalently grafted. These beacons contain in the hairpin loop a target sequence highly conserved in all bacteria, corresponding to a fragment of the 16S ribosomal RNA subunit. The designed single-stranded molecular beacon contained fluorescein as an internal indicator and a quencher in its proximity when not hybridized. Upon hybridization in presence of the target sequence, the indicator and the quencher are spatially separated, resulting in fluorescence enhancement. To perform the assay the developed particles were deposited on different glass fibre strips to obtain a portable and sensitive rapid test. The assays showed that the presence of genomic DNA extracts from bacteria down to 50–70 μg L–1 induced a fluorescence response. The optical read-out was adapted for on-site monitoring by fitting a 3D-printed case to a conventional smartphone, taking advantages of the sensitivity of the CMOS detector. Such embedded assembly enabled the detection of genomic DNA in aqueous extracts down to the mg L–1 range and represents an interesting step toward on-site monitoring of fuel contamination. T2 - IMA 2023 CY - Chania, Greece DA - 18.09.2023 KW - Teststreifen KW - Test strip KW - Microbial KW - Mikrobiell KW - Smartphone KW - Particles KW - Partikeln PY - 2023 AN - OPUS4-58526 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Climent, Estela A1 - Rurack, Knut A1 - Martinez-Manez, R. T1 - Strip-Based Rapid Tests Containing Gated Mesoporous Materials: A Perfect Combination for Sensitivity Improvement N2 - Rapid tests and assays to be used outside of a laboratory for non-trained personal and also at a point of need are becoming increasingly important in areas such as health, food, security, or the environment. Specially on that regard, paper-based sensors are emerging as a new class of devices because they fulfil the requisites of the "World Health Organization" to be ASSURED: affordable, sensitive, specific, user-friendly, rapid and robust, equipment free and deliverable to end-users. The physical, chemical and mechanical properties of cellulose or glass fiber paper in combination with the facility of preparation are making these materials of great interest while looking for cost-efficient and green alternatives for device production technologies. To improve the sensitivity of these systems, a particularly promising approach is the employment of gated indicator delivery systems using preorganized nanoscopic solid structures incorporated on paper strips to produce an exponential amplification of the detectable signal. Having in mind these concepts, several examples of (bio)gated materials incorporated into sensing membranes will be presented for the detection of small organic molecules, having fluorescence or electrochemiluminescence signal as output signal. Compared with fluorescence, it has been demonstrated that the non-optical excitation has significantly reduced the background signal, and with the help of a portable potentiostat in combination with a home-made 3D-printed case fitted onto a smartphone, the sensitivity of the sensing system has been improved tremendously, from the lower ppb range (fluorescence) to the lower ppt range. With this study, the applicability of ECL detection on paper strips in combination with gated indicator-releasing materials has been demonstrated for the first time, presenting a novel synergistic match. Considering the modularity of the system developed, the platform technology potential is obvious, promising expansion of the general concept to many other analytes, applications and scenarios. T2 - XVI International Workshop on Sensors and Molecular Recognition CY - Valencia, Spain DA - 06.07.2023 KW - Schnelltest KW - Vor-Ort-Analytik KW - Lateral Flow Assays KW - Indikatorfreisetzung KW - Fluoreszenz PY - 2023 AN - OPUS4-57966 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -