@misc{MirskySokolovMarkinetal., author = {Mirsky, Vladimir M. and Sokolov, Valeri S. and Markin, Vladislav S. and Chekulaeva, L. N.}, title = {Bilayer lipid membrane formation from bacteriorhodopsin suspension in lipid solution}, series = {Biological membranes}, volume = {1}, journal = {Biological membranes}, issn = {0233-4755}, pages = {1143 -- 1150}, language = {en} } @misc{MirskySokolovMarkin, author = {Mirsky, Vladimir M. and Sokolov, Valeri S. and Markin, Vladislav S.}, title = {Reconstitution of bacteriorhodopsin in bilayer lipid membrane by monolayer method}, series = {Soviet electrochemistry}, volume = {20}, journal = {Soviet electrochemistry}, pages = {876}, language = {en} } @misc{MirskySokolovMelniketal., author = {Mirsky, Vladimir M. and Sokolov, Valeri S. and Melnik, E. I. and Diukova, T. V.}, title = {A study of incorporation of bacteriorhodopsin into bimolecular lipid membranes}, series = {Biophysics}, volume = {29}, journal = {Biophysics}, issn = {0006-3029}, pages = {250 -- 253}, language = {en} } @misc{MirskySokolov, author = {Mirsky, Vladimir M. and Sokolov, Valeri S.}, title = {Criteria of bacteriorhodopsin incorporation into bimolecular lipid membrane}, series = {Biophysics}, volume = {29}, journal = {Biophysics}, issn = {0006-3029}, pages = {246 -- 249}, language = {en} } @misc{MirskySokolovDiukovaetal., author = {Mirsky, Vladimir M. and Sokolov, Valeri S. and Diukova, T. V. and Melnik, E. I.}, title = {A study of bacteriorhodopsin-containing proteoliposome incorporation into bimolecular lipid membranes}, series = {Bioelectrochemistry and Bioenergetics}, volume = {11}, journal = {Bioelectrochemistry and Bioenergetics}, number = {4-6}, issn = {0302-4598}, pages = {327 -- 346}, abstract = {The photoresponses of planar bimolecular lipid membranes (BLM) modified with liposomes containing bacteriorhodopsin (BR) were investigated in the presence of Ca 2+ cations. Short-circuit currents during switch-on and switch-off of the light were measured within a time scale exceeding the BR photocycle, and the dependence of the currents on external field and membrane conductance was studied. A comparison of the experimental data with computed values indicates that the photoresponses observed are due not only to BR contained in the proteoliposomes adhered to the BLM, as generally believed, but also to BR in BLM itself. The transfer of BR to BLM may result from the complete fusion of liposomes with the planar membrane. The existence of such a transfer is indicative of the possibility of obtaining the most convenient model system for BR studies: a planar bimolecular lipid membrane containing incorporated BR.}, language = {en} } @misc{EfremenkoMirsky, author = {Efremenko, Yulia and Mirsky, Vladimir M.}, title = {Virtual sensor array consisting of a single sensor element with variable affinity: an application for analysis of fish freshness}, series = {Sensors and Actuators B: Chemical}, volume = {241}, journal = {Sensors and Actuators B: Chemical}, issn = {0925-4005}, doi = {10.1016/j.snb.2016.10.126}, pages = {652 -- 657}, abstract = {Recently reported concept of electrical control of sensor affinity was applied for formation of a virtual sensor array based on the single sensing element. Affinity properties of this element were modulated by electrically controlled conversion of chemosensitive material between its different redox states possessing different affinity. The sensor was realized on the basis of electrochemical chemotransistor in which a low temperature ionic liquid containing chloride was used to connect the chemosensitive material to the Ag/AgCl reference electrode. The concept of virtual array was proved by its application for monitoring of fish headspace. Using three characteristics of the sensor response measured at three different redox states of the same sensor material, we have obtained signals from a virtual sensor array consisting of nine chemosensitive elements. The sensor displays systematic changes of its nine signals during fish degradation and allows us to make quantitative analysis of its freshness defined as the after the catch. The level of detection is far below the level of organoleptic detection.}, language = {en} } @misc{ShishkanovaHavlikKraletal., author = {Shishkanova, Tatiana V. and Havlik, Martin and Kr{\´a}l, Vladim{\´i}r and Kopeck{\´y}, Dušan and Matějka, Pavel and Dendisov{\´a}, Marcela and Mirsky, Vladimir M.}, title = {Amino-substituted Tr{\"o}ger's base: electrochemical polymerization and characterization of the polymer film}, series = {Electrochimica Acta}, volume = {224}, journal = {Electrochimica Acta}, issn = {0013-4686}, doi = {10.1016/j.electacta.2016.12.061}, pages = {439 -- 445}, abstract = {The amino-substituted coumarin derivative of Tr{\"o}ger's base (CTB) was electrochemically polymerized on the surface of gold electrodes. The obtained polymer films were characterized by SEM, Raman spectroscopy, cyclic voltammetry and in-situ conductometry. Spectroscopic analysis indicates that the polymerization of CTB takes place via oxidation of the aniline fragment of CTB molecule, similar to the polymerization of aniline. The similarity of the polymer backbone to that of the polyaniline is also confirmed by the influence of potential on the film's conductivity, however the conductivity of the new material is in principle lower than that of polyaniline. SEM shows that the polymer forms a thin layer with a thickness of ~ 100 nm. Possible applications of the new material as an artificial receptor for aromatic analytes containing carboxy-group are proposed.}, language = {en} } @misc{NizamovScherbahnMirsky, author = {Nizamov, Shavkat and Scherbahn, Vitali and Mirsky, Vladimir M.}, title = {Ionic referencing in surface plasmon microscopy: visualization of the difference in surface properties of patterned monomolecular layers}, series = {Analytical Chemistry}, volume = {89}, journal = {Analytical Chemistry}, number = {7}, issn = {0003-2700}, doi = {10.1021/acs.analchem.7b00251}, pages = {3873 -- 3878}, abstract = {An approach for visualization of patterned monomolecular layers in surface plasmon microscopy (SPM) is suggested. The development of hidden image in SPM is achieved by referencing of images obtained in the presence of electrolytes with a high molar refraction of either anions or cations. A formation of diffuse layer near the charged surface areas leads to the redistribution of ions. The ratio of SPM images allows one to visualize this redistribution and to distinguish surface areas with different properties. The approach is unobtrusive and robust; it can be used with most SPR imaging instruments.}, language = {en} } @inproceedings{NizamovScherbahnMirsky, author = {Nizamov, Shavkat and Scherbahn, Vitali and Mirsky, Vladimir M.}, title = {Advanced wide-field surface plasmon microscopy of single adsorbing nanoparticles}, series = {Optical Sensors 2017, 24-27 April 2017 Prague, Czech Republic}, booktitle = {Optical Sensors 2017, 24-27 April 2017 Prague, Czech Republic}, publisher = {SPIE}, address = {Bellingham, Washington}, isbn = {978-1-5106-0963-1}, doi = {10.1117/12.2267144}, abstract = {In-situ detection and characterization of nanoparticles in biological media as well as in food or other complex samples is still a big challenge for existing analytical methods. Here we describe a label-free and cost-effective analytical method for detection of nanoparticles in the concentration range 106 -1010 NPs/ml. The proposed method is based on the surface plasmon resonance microscopy (SPRM) with a large field of view (~1.3mm2 ). It is able to detect and count adsorbing nanoparticles individually, totally up to the hundreds of thousands of NPs on the sensor surface. At constant diffusion conditions the detection rate is proportional to the number concentration of NPs, this provides an approach to determine the NPs concentration. The adsorption of nanoparticle can be manipulated by the surface functionalization, pH and electrolyte concentration of suspensions. Images of detected nanoparticles can be quantified in order to characterize them individually. The image intensity grows quasi-linearly with nanoparticle size for the given material. However, the size and material of nanoparticle cannot be resolved directly from the image. For determination of chemical composition, SPRM can be assisted by electrochemical analysis. In this case, the gold sensor surface is used both as a resonant media for plasmon microscopy and as a working electrode. Under potential sweep, the adsorbed NPs can be subjected to electrochemical dissolution, which is detected optically. The potential of this conversion characterizes the material of NPs.}, language = {en} } @inproceedings{NizamovScherbahnMirsky, author = {Nizamov, Shavkat and Scherbahn, Vitali and Mirsky, Vladimir M.}, title = {Wide-field surface plasmon microscopy of nano- and microparticles: features, benchmarking, limitations, and bioanalytical applications}, series = {Optical Sensors 2017, 24-27 April 2017, Prague, Czech Republic}, booktitle = {Optical Sensors 2017, 24-27 April 2017, Prague, Czech Republic}, publisher = {SPIE}, address = {Bellingham, Washington, USA}, isbn = {978-1-5106-0963-1}, doi = {10.1117/12.2267158}, abstract = {Detection of nano- and micro-particles is an important task for chemical analytics, food industry, biotechnology, environmental monitoring and many other fields of science and industry. For this purpose, a method based on the detection and analysis of minute signals in surface plasmon resonance images due to adsorption of single nanopartciles was developed. This new technology allows one a real-time detection of interaction of single nano- and micro-particles with sensor surface. Adsorption of each nanoparticle leads to characteristic diffraction image whose intensity depends on the size and chemical composition of the particle. The adsorption rate characterizes volume concentration of nano- and micro-particles. Large monitored surface area of sensor enables a high dynamic range of counting and to a correspondingly high dynamic range in concentration scale. Depending on the type of particles and experimental conditions, the detection limit for aqueous samples can be below 1000 particles per microliter. For application of method in complex media, nanoparticle images are discriminated from image perturbations due to matrix components. First, the characteristic SPRM images of nanoparticles (templates) are collected in aqueous suspensions or spiked real samples. Then, the detection of nanoparticles in complex media using template matching is performed. The detection of various NPs in consumer products like cosmetics, mineral water, juices, and wines was shown at sub-ppb level. The method can be applied for ultrasensitive detection and analysis of nano- and micro-particles of biological (bacteria, viruses, endosomes), biotechnological (liposomes, protein nanoparticles for drug delivery) or technical origin.}, language = {en} } @misc{LaurinavichyuteNizamovMirsky, author = {Laurinavichyute, Veronika K. and Nizamov, Shavkat and Mirsky, Vladimir M.}, title = {The Role of Anion Adsorption in the Effect of Electrode Potential on Surface Plasmon Resonance Response}, series = {ChemPhysChem : a European journal of physical chemistry and chemical physics}, volume = {18}, journal = {ChemPhysChem : a European journal of physical chemistry and chemical physics}, number = {12}, issn = {1439-7641}, doi = {10.1002/cphc.201601288}, pages = {1552 -- 1560}, abstract = {Surface plasmon resonance, being widely used in bioanalytics and biotechnology, is influenced by the electrical potential of the resonant gold layer. To evaluate the mechanism of this effect, we have studied it in solutions of various inorganic electrolytes. The magnitude of the effect decreases according to the series: KBr>KCl>KF>NaClO4. The data were treated by using different models of the interface. A quantitative description was obtained for the model, which takes into account the local dielectric function of gold being affected by the free electron charge, diffuse ionic layer near the gold/water interface, and specific adsorption of halides to the gold surface with partial charge transfer. Taking into account that most biological experiments are performed in chloride-containing solutions, detailed analysis of the model at these conditions was performed. The results indicate that the chloride adsorption is the main mechanism for the influence of potential on the surface plasmon resonance. The dependencies of surface concentration and residual charge of chloride on the applied potential were determined.}, language = {en} } @periodical{OPUS4-21635, title = {Microchimica Acta}, editor = {Mirsky, Vladimir M.}, publisher = {Springer}, address = {Heidelberg [u.a.]}, issn = {1436-5073}, abstract = {181.2014-184.2017}, language = {en} } @periodical{OPUS4-21639, title = {Russian Journal of Electrochemistry}, editor = {Mirsky, Vladimir M.}, publisher = {Springer}, address = {Heidelberg}, issn = {1023-1935}, abstract = {52.2016-53.2017}, language = {en} } @periodical{OPUS4-21641, title = {Sensors}, editor = {Mirsky, Vladimir M.}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, abstract = {9.2009-17.2017}, language = {en} } @periodical{OPUS4-21666, title = {Journal of Biological Physics and Chemistry}, editor = {Mirsky, Vladimir M.}, publisher = {JBPC}, address = {Basel}, issn = {1512-0856}, abstract = {8.2008-17.2017}, language = {en} } @periodical{OPUS4-21669, title = {Journal of Functional Biomaterials}, editor = {Mirsky, Vladimir M.}, publisher = {MDPI}, address = {Basel}, issn = {2079-4983}, abstract = {5.2014-8.2017}, language = {en} } @misc{MirskyRoedigerSchieracketal., author = {Mirsky, Vladimir M. and R{\"o}diger, Stefan and Schierack, Peter and Roggenbuck, Dirk}, title = {Preface to the Special Issue on PCR on chip and related technologies}, series = {Microchimica Acta}, volume = {181}, journal = {Microchimica Acta}, number = {13/14}, doi = {10.1007/s00604-014-1246-1}, pages = {1609 -- 1610}, language = {en} } @incollection{ScherbahnNizamovMirsky, author = {Scherbahn, Vitali and Nizamov, Shavkat and Mirsky, Vladimir M.}, title = {Toward ultrasensitive surface plasmon resonance sensors}, series = {Label-free biosensing : advanced materials, devices and applications}, booktitle = {Label-free biosensing : advanced materials, devices and applications}, editor = {Sch{\"o}ning, Michael J. and Poghossian, Arshak}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-75220-4}, doi = {https://doi.org/10.1007/5346_2017_21}, pages = {409 -- 448}, abstract = {Despite the history of application of surface plasmon resonance (SPR) for chemo- and biosensing being over 30 years long, the development of this technique is still in progress. This review is focused on the technological aspects of further improvement of analytical performance of SPR transducers based on Kretschmann configuration. We describe basic measurement configurations, their improvements and optimizations, and their drawbacks and limitations. An importance of referencing in SPR sensors is highlighted. The referencing approaches are classified into the following domains: (1) macroscopic spatially separated referencing, (2) self-referencing based on micro-patterning, (3) in-place referencing, (4) spatiotemporal referencing, and (5) electrochemically assisted referencing. The underlying principles of these approaches, examples of their implementation, and resulting improvements of sensor performance are described. Finally, an analysis of SPR data and an extraction of affinity properties are discussed.}, language = {en} } @misc{GuticKozlicaBajukBogdanovicetal., author = {Gutic, Sanjin J. and Kozlica, Dzevad K. and Bajuk-Bogdanovic, Danica and Mitric, Miodrag and Mirsky, Vladimir M. and Mentus, Slavko V. and Pasti, Igor A.}, title = {Electrochemical tuning of capacitive response of graphene oxide}, series = {Physical Chemistry, Chemical Physics}, volume = {35}, journal = {Physical Chemistry, Chemical Physics}, number = {20}, issn = {1463-9084}, doi = {10.1039/C8CP03631D}, pages = {22698 -- 22709}, abstract = {The increasing energy demands of modern society require a deep understanding of the properties of energy storage materials, as well as the tuning of their performance. We show that the capacitance of graphene oxide (GO) can be precisely tuned using a simple electrochemical reduction route. In situ resistance measurements, in combination with cyclic voltammetry measurements and Raman spectroscopy, have shown that upon reduction GO is irreversibly deoxygenated, which is further accompanied by structural ordering and an increase in electrical conductivity. The capacitance is maximized when the concentration of oxygen functional groups is properly balanced with the conductivity. Any further reduction and deoxygenation leads to a gradual loss of capacitance. The observed trend is independent of the preparation route and the exact chemical and structural properties of GO. It is proposed that an improvement in the capacitive properties of any GO can be achieved by optimization of its reduction conditions.}, language = {en} } @misc{HammamiRaouafiMirsky, author = {Hammami, Asma and Raouafi, Noureddine and Mirsky, Vladimir M.}, title = {Electrically controlled Michael addition: Addressing of covalent immobilization of biological receptors}, series = {Biosensors and Bioelectronics}, volume = {121}, journal = {Biosensors and Bioelectronics}, issn = {1873-4235}, doi = {10.1016/j.bios.2018.08.044}, pages = {72 -- 79}, abstract = {Electrically addressed covalent immobilization of biomolecules to the defined electrodes of an electrode array is described. It is based on Michael addition of the thiol group of biomolecules to α,β-unsaturated carbonyl groups of benzoquinone. This "click" reaction was tested by immobilization of a number of thiolated compounds on the simplest array consisting of two gold electrodes coated by a self-assembled monolayer of benzoquinone-terminated hexanethiol. Electrically controlled binding of hexanethiol, ferrocenylhexanethiol, human serum albumin and thiol-terminated single-stranded DNA (ssDNA) was investigated. The binding was studied using cyclic voltammetry, X-ray photoelectron spectroscopy and surface plasmon resonance. The reaction requires the oxidized state of the benzoquinone moiety; this can be reached by applying of a moderate anodic potential to the electrode. Surface plasmon resonance measurements demonstrated that the thiol-modified ssDNA immobilized by this technique binds complementary synthetic oligonucleotides or PCR-amplified DNA fragments. The developed technology of electrical addressing of covalent immobilization can be applied for fabrication of sensor arrays.}, language = {en} } @misc{TonderNizamovScherbahnetal., author = {Tonder, Karin and Nizamov, Shavkat and Scherbahn, Vitali and Mirsky, Vladimir M.}, title = {Das Unsichtbare im Blick Ultrasensitive Detektion, Quantifizierung und Identifizierung industriell erzeugter und biologischer Nanopartikel}, series = {Laborpraxis}, volume = {42}, journal = {Laborpraxis}, number = {1}, issn = {0344-1733}, pages = {24 -- 26}, language = {de} } @misc{Mirsky, author = {Mirsky, Vladimir M.}, title = {Nanodetector: Ultrasensitive plasmonic detection of single nanoparticles}, series = {Compendium of Projects in the European Nanosafety Cluster}, volume = {2012}, journal = {Compendium of Projects in the European Nanosafety Cluster}, pages = {79 -- 83}, language = {en} } @misc{Mirsky, author = {Mirsky, Vladimir M.}, title = {Nanodetector: Ultrasensitive plasmonic detection of single nanoparticles}, series = {Compendium of Projects in the European Nanosafety Cluster}, volume = {2013}, journal = {Compendium of Projects in the European Nanosafety Cluster}, pages = {85 -- 89}, language = {en} } @misc{Mirsky, author = {Mirsky, Vladimir M.}, title = {Nanodetector: Ultrasensitive plasmonic detection of single nanoparticles}, series = {Compendium of Projects in the European Nanosafety Cluster}, volume = {2014}, journal = {Compendium of Projects in the European Nanosafety Cluster}, pages = {54 -- 59}, language = {en} } @misc{Mirsky, author = {Mirsky, Vladimir M.}, title = {Nanodetector: Ultrasensitive plasmonic detection of single nanoparticles}, series = {Compendium of Projects in the European Nanosafety Cluster}, volume = {2015}, journal = {Compendium of Projects in the European Nanosafety Cluster}, pages = {83 -- 89}, language = {en} } @incollection{NizamovMirsky, author = {Nizamov, Shavkat and Mirsky, Vladimir M.}, title = {Wide-field Surface Plasmon Resonance Microscopy for in-situ Characterization of Nanoparticle Suspensions}, series = {In-situ characterization techniques for nanomaterials}, booktitle = {In-situ characterization techniques for nanomaterials}, editor = {Kumar, Challa S. S. R.}, publisher = {Springer Verlag}, address = {Heidelberg}, isbn = {978-3-662-56322-9}, doi = {10.1007/978-3-662-56322-9}, pages = {61 -- 106}, language = {en} } @misc{LaroussiKotFlegeetal., author = {Laroussi, Arwa and Kot, Małgorzata and Flege, Jan Ingo and Raouafi, Noureddine and Mirsky, Vladimir M.}, title = {Self-assembled monolayers from symmetrical di-thiols: Preparation, characterization and application for the assembly of electrochemically active films}, series = {Applied Surface Science}, volume = {513}, journal = {Applied Surface Science}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2020.145827}, abstract = {1,3-dimercaptopropan-2-ol, a symmetrical di-thiol, has been synthesized and applied as a new type of anchor molecule to prepare a self-assembled monolayer (SAM) on the gold surface. The formed monolayers were studied by cyclic voltammetry, impedance spectroscopy, X-ray photoelectron spectroscopy, kinetic capacitance, and contact angle measurements. The SAM structure depends on the adsorption conditions. A short incubation time of the electrode at high concentration of this di-thiol leads to the predominating binding through one thiol group of the adsorbate to the gold surface, while a long incubation at low concentration leads to the predominating binding by both thiol groups. A comparative study of the desorption and replacement of SAMs indicates a strong stability increase when the SAM molecules bond gold surface by two bonds mainly. This monolayer was used to immobilize electrochemically active p-benzoquinone moiety. The surface concentration of p-benzoquinone obtained from cyclic voltammetry is 2.5 ± 0.2 × 10-10 mol·cm-2 which corresponds to the functionalization of 65 ± 5\% of SAM molecules. The obtained highly stable SAM with redox-active terminal group can be applied for different tasks of chemical sensing and biosensing. As an example, an application of this system for electrocatalytical oxidation of dihydronicotinamide adenosine dinucleotide (NADH) was tested.}, language = {en} } @misc{Mirsky, author = {Mirsky, Vladimir M.}, title = {Electrochemical sensors between the academic world and harsh reality: a few thoughts on the past, present, and future}, series = {Journal of Solid State Electrochemistry}, volume = {24}, journal = {Journal of Solid State Electrochemistry}, number = {9}, issn = {1433-0768}, doi = {10.1007/s10008-020-04711-1}, pages = {2147 -- 2149}, language = {en} } @misc{EfremenkoMirsky, author = {Efremenko, Yulia and Mirsky, Vladimir M.}, title = {Poly-3-thienylboronic acid: a chemosensitive derivative of polythiophene}, series = {Journal of Solid State Electrochemistry}, volume = {24}, journal = {Journal of Solid State Electrochemistry}, number = {11-12}, issn = {1433-0768}, doi = {10.1007/s10008-020-04767-z}, pages = {3105 -- 3111}, abstract = {Poly-3-thiopheneboronic acid was synthesized by electrochemical polymerization from 3-thienylboronic acid dissolved in the mixture of boron trifluoride diethyl etherate and acetonitrile. Cyclic voltammetry during electropolymerization shows oxidative and reductive peaks growing in each next cycle. An investigation by scanning electron microscopy displayed the polymer layer like a highly flexible film of 110 nm thick with grains of 60-120 nm in size. Strong negative solvatochromic effect was observed. Optical spectra of poly-3-thienylboronic acid at different potentials and pH were studied. Potential cycling leads to a well reversible electrochromic effect. At pH 7.4, the increase of potential leads to the decrease in the absorption band at 480 nm and to the rise in the absorption band at 810 nm with an isosbestic point at 585 nm. Spectroelectrochemical behavior of poly-3-thienylboronic acid and polythiophene was compared. Binding of sorbitol at fixed electrode potential leads to an increase in the absorbance in the shortwave band and to the decrease in the longwave band; the effect depends on the electrode potential and pH. Perspectives of application of poly-3-thienylboronic acid as new chemosensitive material are discussed.}, language = {en} } @misc{SnopokLaroussiCafollaetal., author = {Snopok, Borys A. and Laroussi, Arwa and Cafolla, Clodomiro and Voitchovsky, Kislon and Snopok, Tetiana V. and Mirsky, Vladimir M.}, title = {Gold surface cleaning by etching polishing: Optimization of polycrystalline film topography and surface functionality for biosensing}, series = {Surfaces and Interfaces}, volume = {22}, journal = {Surfaces and Interfaces}, issn = {2468-0230}, doi = {10.1016/j.surfin.2020.100818}, pages = {11}, abstract = {Modern bio-chemical sensors rely on functional interfacial architectures with well-defined structural nano-motifs over a physical transducer. Gold-coated interfaces are of particular interest for their desirable chemical (functionalization) and optical (plasmonic) properties. Here we investigate the cleaning and polishing of polycrystalline gold films in preparation of advanced surface functionalization. We focus on soft wet chemical etching to decrease the small-scale roughness commonly observed after evaporation or sputtering of gold. We show that optimized surfaces are obtained by etching in solutions of hydrochloric acid and hydrogen peroxide. We systematically quantify the films wettability, surface nano-topography, UV-VIS spectrum and the electrochemical and Surface Plasmon Resonance (SPR) changes throughout the etching process. Optimal results are obtained by etching with a HCl(37\%):H2O2(30\%):H2O mixture, with a volume ratio of reagents 3:3:94 during 15-20 minutes at room temperature for the main step. This reduces by a factor two the root-mean-square roughness, removes contaminants, increases hydrophilicity and modifies the gold surface by Au(Cl)x complexes. Significantly, the resulting the surface is hydrophilic enough to prevent globular proteins such as HSA to unfold upon deposition at concentrations more than ~1 mg/mL. Our protocol offers a simple, reliable and rapid method for the preparation of gold surface in view of further functionalization including the binding of receptor layers and various micro- and nanostructures required in chemical and biochemical sensing.}, language = {en} } @misc{LaurinavichyuteNizamovMirsky, author = {Laurinavichyute, Veronika K. and Nizamov, Shavkat and Mirsky, Vladimir M.}, title = {Real time tracking of the early stage of electrochemical nucleation}, series = {Electrochimica Acta}, volume = {382}, journal = {Electrochimica Acta}, issn = {0013-4686}, doi = {10.1016/j.electacta.2021.138278}, pages = {8}, abstract = {An analysis of early stage of electrochemical nucleation is crucial in order to understand the mechanism of this process and for electrochemical synthesis of new materials. We show here an application of the wide field surface plasmon microscopy (WF-SPRM) for this purpose. It allows us in-situ monitoring of the growth of nuclei in the range from ~20 till over 1000 nm. The system registers the moment and the place of the formation of each individual nucleus for the total number of the tracked nuclei up to ~10,000 per 1 mm2. The results demonstrate that the integral information obtained from electrochemical measurements can be extracted quantitatively from optical measurements while optical data provide also information on the size of each individual nucleus, individual nucleation time, localization and growth kinetics, and allows one to distinguish the rate limiting stage for each individual nucleus. In this work WF-SPRM was applied for investigation of electrochemical deposition of copper on gold, but this technique can be extended easily to other materials or other nucleation types.}, language = {en} } @misc{LaroussiRaouafiMirsky, author = {Laroussi, Arwa and Raouafi, Noureddine and Mirsky, Vladimir M.}, title = {Electrocatalytic Sensor for Hydrogen Peroxide Based on Immobilized Benzoquinone}, series = {Electroanalysis}, volume = {33}, journal = {Electroanalysis}, number = {9}, issn = {1521-4109}, doi = {10.1002/elan.202100113}, pages = {2062 -- 2070}, abstract = {An amperometric chemosensor for the detection of hydrogen peroxide is reported. The sensor is based on 1,4-benzoquinone immobilized on the gold electrode using self-assembled monolayer of short chain symmetrical dithiol as an anchor layer. Sensor analysis was performed by cyclic voltammetry at the potential range from -0.6 V till +0.9 V as well as in the anodic or cathodic potential ranges only. The results indicate oxidative electrochemical decomposition of hydrogen peroxide at the potential of ∼+0.4 V leading to the formation of oxygen while at cathodic potentials a reduction of the formed oxygen as well as of the hydrogen peroxide occur. A decrease in the oxidation potential of hydrogen peroxide on the gold electrode coated by self-assembled monolayer with 1,4-benzoquinone in comparison with that measured on the electrodes coated by the same self-assembled monolayer without 1,4-benzoquinone, indicates electrocatalytic effect of this moiety on oxidative decomposition of hydrogen peroxide. Analytical evaluation of the sensor performance was done in the voltammetric as well as in the chronoamperometric mode. The sensor exhibited linear response over the concentration range till 2.5 mM with a limit of detection ∼4 μM.}, language = {en} } @misc{LaroussiKotFlegeetal., author = {Laroussi, Arwa and Kot, Małgorzata and Flege, Jan Ingo and Raouafi, Noureddine and Mirsky, Vladimir M.}, title = {Self-Assembled Monolayers from Symmetrical Di-Thiols: Preparation, Characterization and Application for the Assembly of Electrochemically Active Films}, series = {Engineering Proceedings}, volume = {6}, journal = {Engineering Proceedings}, number = {1}, issn = {2673-4591}, doi = {10.3390/I3S2021Dresden-10112}, abstract = {1,3-dimercaptopropan-2-ol, a symmetrical di-thiol, has been synthesized and applied as a new type of anchor molecule to prepare a self-assembled monolayer (SAM) on a gold surface. The formed monolayers were studied by cyclic voltammetry, impedance spectroscopy, X-ray photoelectron spectroscopy, kinetic capacitance, and contact angle measurements. The SAM structure depends on the adsorption conditions. A short incubation time of the electrode at high concentration of this di-thiol leads to the predominating binding through one thiol group of the adsorbate to the gold surface, while a long incubation at low concentration leads to the predominating binding by both thiol groups. A comparative study of the desorption and replacement of SAMs indicates a strong stability increase when the SAM molecules bond gold surfaces by two bonds mainly. This monolayer was used to immobilize electrochemically active p-benzoquinone moiety. The surface concentration of p-benzoquinone obtained from cyclic voltammetry is 2.5 ± 0.2 × 10-10 mol cm-2, which corresponds to the functionalization of 65 ± 5\% of SAM molecules. The obtained highly stable SAM with redox-active terminal group can be applied for different tasks of chemical sensing and biosensing. As an example, an application of this system for electrocatalytical oxidation of dihydronicotinamide adenosine dinucleotide (NADH) was tested.}, language = {en} } @misc{NizamovDimchevskaSazdovskaMirsky, author = {Nizamov, Shavkat and Dimchevska Sazdovska, Simona and Mirsky, Vladimir M.}, title = {A review of optical methods for ultrasensitive detection and characterization of nanoparticles in liquid media with a focus on the wide field surface plasmon microscopy}, series = {Analytica Chimica Acta}, volume = {1204}, journal = {Analytica Chimica Acta}, issn = {1873-4324}, doi = {10.1016/j.aca.2022.339633}, pages = {32}, abstract = {Development of nanotechnology and corresponding industries during the last decade resulted in a new challenge for analytical science. This includes an ultrasensitive detection and characterization of nanoparticles of different origin and other nanomaterials in various media, including so complex ones as food, biological or environmental samples. The goal of this review is a systematic analysis of possible approaches and description of physical principles behind these methods. The main attention is paid to optical methods which are considered by authors to be mostly effective for the formulated task. Different approaches for detection and analysis of nanoparticles in a volume as well as of those adsorbed on a surface are discussed. While the technologies based on direct analysis of nanoparticle suspensions belong to the established approaches whose development potential has been in large extent exhausted, the novel technologies based on the surface sensing of adsorbed nanoparticles demonstrate intensive development. Therefore, the final part of the review is focused on the wide-field surface plasmon resonance microscopy. It allows one an ultrasensitive detection and characterization of individual nanoparticles of different origin in complex media and provides numerous possibilities for subsequent chemical identification of the detected particles using a hyphenation with other analytical technologies.}, language = {en} } @misc{KaračićGutićVasićetal., author = {Karačić, Dalibor and Gutić, Sanjin J. and Vasić, Borislav and Mirsky, Vladimir M. and Skorodumova, Natalia V. and Mentus, Slavko V. and Pašti, Igor A.}, title = {Electrochemical reduction of thin graphene-oxide films in aqueous solutions - Restoration of conductivity}, series = {Electrochimica Acta}, volume = {410}, journal = {Electrochimica Acta}, issn = {1873-3859}, doi = {10.1016/j.electacta.2022.140046}, pages = {11}, abstract = {Graphene oxide finds applications in different fields of science, including energy conversion. Electrochemical reduction of graphene oxide (GO) significantly improves its conductivity. However, the kinetics of this process depends on the solvent, supporting electrolyte, pH, and numerous other factors. Most studies report the macroscopic views and ex-situ properties of reduced GO. To expand the knowledge about GO reduction, in this study, we used cyclic voltammetry (CV), simultaneous 2 points and 4 points resistance measurement (s24), conductive atomic force microscopy (AFM), and theoretical calculations. Using CV, we demonstrated that the choice of supporting electrolyte (KCl or LiCl) influences the potential range in which electrochemical GO reduction occurs. The activation energy of this process was estimated to be below 30 kJ mol‒1 in both electrolytes, being significantly lower than that required for thermal reduction of GO. Simultaneous in situ s24 resistance measurements suggest that GO films reach a highly conductive state at deep negative potentials, with an abrupt, irreversible switch from non-conductive to the conductive state. However, conductive AFM presents a more exact picture of this process: the reduction of GO films starts locally while the formed conductive islands grow during the reduction. This mechanism was confirmed by theoretical calculations indicating that the reduction starts on isolated oxygen-functional groups over the GO basal plane, while clustered OH groups are more difficult to reduce. The presented results can help in tailoring reduced GO for a particular electrochemical application by precisely controlling the reduction degree and percentage of the conductive area of the reduced GO films.}, language = {en} } @misc{EfremenkoMirsky, author = {Efremenko, Yulia and Mirsky, Vladimir M.}, title = {3-Thienylboronic Acid as a Receptor for Diol-Containing Compounds: A Study by Isothermal Titration Calorimetry}, series = {Chemosensors}, volume = {10}, journal = {Chemosensors}, number = {7}, issn = {2227-9040}, doi = {10.3390/chemosensors10070251}, abstract = {The electrochemical activity of 3-thienylboronic acid and its feature to form polymer films makes it a perspective receptor material for sensor applications. The affinity properties of this compound were studied here by isothermal titration calorimetry. A number of different analytes were tested, and the highest binding enthalpy was observed for sorbitol and fructose. An increase of pH in the range of 5.5-10.6 results in the rise of the binding enthalpy with an increase of the binding constant to ~8400 L/mol for sorbitol or ~3400 L/mol for fructose. The dependence of the binding constant on pH has an inflection point at pH 7.6 with a slope that is a ten-fold binding constant per one pH unit. The binding properties of 3-thienylboronic acid were evaluated to be very close to that of the phenylboronic acid, but the electrochemical activity of 3-thienylboronic acid provides a possibility of external electrical control: dependence of the affinity of 3-thienylboronic acid on its redox state defined by the presence of ferro/ferricyanide in different ratios was demonstrated. The results show that 3-thienylboronic acid can be applied in smart chemical sensors with electrochemically controllable receptor affinity.}, language = {en} } @misc{EfremenkoMirsky, author = {Efremenko, Yulia and Mirsky, Vladimir M.}, title = {Electrical Control of the Receptor Affinity}, series = {Engineering Proceedings}, volume = {6}, journal = {Engineering Proceedings}, number = {1}, issn = {2673-4591}, doi = {10.3390/I3S2021Dresden-10084}, abstract = {A concept of virtual sensor array based on an electrically controlled variation of affinity properties of the receptor layer was realized on the base of integrated electrochemical chemotransistor containing conducting polymer as the receptor layer. Electrical control of the redox-state of the polymer (polyaniline) was performed in a five-electrode configuration with four electrodes for conductivity measurements and Ag/AgCl reference electrode integrated on the same glass chip. An ionic liquid provided an electrical connection between the reference electrode and chemosensitive material. Conductivity measurements demonstrated potential controlled electrochemical conversions of the receptor material between different redox states. The binding of trimethylamine at three different potentials corresponding to these states was studied. The results demonstrated that both kinetic- and equilibrium-binding properties of the receptor are controlled by the electrical potential, thus providing a possibility to form a virtual sensor array using only a single sensing element. The concept was applied for monitoring fish headspace. Using three characteristics of the sensor response measured at three different redox states of the same sensor material, we obtained signals from a virtual sensor array consisting of nine chemosensitive elements. The sensor displays systematic changes of its nine signals during fish degradation. This approach can be applied also for the electrical control of the affinity of immunoglobulins. Development of new materials with electrically controlled affinity is in progress.}, language = {en} } @misc{NizamovScherbahnMirsky, author = {Nizamov, Shavkat and Scherbahn, Vitali and Mirsky, Vladimir M.}, title = {Detection of Single Sub-Micrometer Objects of Biological or Technical Origin Using Wide Field Surface Plasmon Microscopy}, series = {MDPI Proceedings (Journal), Proceedings of the 5th International Symposium on Sensor Science (I3S 2017))}, volume = {1}, journal = {MDPI Proceedings (Journal), Proceedings of the 5th International Symposium on Sensor Science (I3S 2017))}, number = {8}, publisher = {MDPI}, address = {Basel, Switzerland}, doi = {10.3390/proceedings1080788}, pages = {1}, abstract = {Detection of nano- and microparticles is an important task for chemical analytics, medical diagnostics, food industry, biotechnology, environmental monitoring and many other fields of science and industry. For this purpose, a method based on the detection and analysis of minute signals of surface plasmon resonance images due to adsorption of single particles was developed. The new technology allows one a real-time detection of interaction of single nano- and microparticles of different origin with sensor surface. Adsorption of each nanoparticle leads to a characteristic diffraction image whose intensity depends on the size and chemical composition of the particle. The number of the nanoparticle - surface binding events per time and surface area characterizes volume concentration. A large monitored surface area of the sensor surface allows one to detect many hundreds events in each frame or totally up to a million particles on the sensor surface, this leads to a very high dynamic range of counting and to a correspondingly high dynamic range in the concentration scale. Depending on the type of particles and experimental conditions, the detection limit for aqueous samples can be below 1000 nanoparticles per microliter. Stable analysis of nanoparticles in very complex environment (fruit juices, wines, cosmetic formulations) was demonstrated. For determination of chemical composition of single nanoparticles separately, the wide field surface plasmon microscopy can be used as a tandem technique. For example, for analysis of technical nanoparticles it can be assisted by electrochemical analysis. In this case, the gold sensor surface is used both for plasmon microscopy and as a working electrode of electrochemical cell. Applying a linear potential sweep to this electrode, adsorbed nanoparticles can be subjected to an electrochemical conversion leading to the change of their refractive index; the value of electrical potential of this conversion characterizes material of the particular nanoparticle. Notably, such analysis is performed simultaneously but independently for each adsorbed particle. The method of wide filed surface plasmon microscopy can be applied for ultrasensitive detection and analysis of nano- and microparticles of biological (bacteria, viruses, exosomes), biotechnological, (liposomes, protein nanoparticles for drug delivery) or technical (metallic, oxides, plastic, etc.) origin.}, language = {en} } @misc{EfremenkoLaroussiSengueletal., author = {Efremenko, Yulia and Laroussi, Arwa and Seng{\"u}l, Akant and Corley-Wiciak, Agnieszka Anna and Fischer, Inga Anita and Mirsky, Vladimir M.}, title = {Deposition of Polymers on Titanium Nitride Electrodes}, series = {Coatings}, volume = {14}, journal = {Coatings}, number = {2}, issn = {2079-6412}, doi = {10.3390/coatings14020215}, abstract = {The application of titanium nitride (TiN) as an electrode for electrochemical deposition or characterization requires the removal of an insulating layer from its surface. This process was studied and optimized, and the conditions for the complete removal of this layer through treatment with oxalic acid were formulated. The obtained TiN surfaces were used for the deposition of various conducting and non-conducting polymers. Two different approaches were applied: (i) in situ electrochemical synthesis of the main classes of conducting polymers, including polyaniline, polypyrrole, polythiophene, and selected derivatives thereof, and (ii) electrostatically driven layer-by-layer (LbL) deposition of multilayers of oppositely charged polyelectrolytes. The deposited polymers were characterized by electrochemical methods. The electrochemical properties of the deposited conducting polymers and their deposition on the TiN surface were comparable to those of the metallic electrodes. The films produced via LbL deposition exhibited a pronounced influence of the charge of the last deposited polymer on the redox reaction of ferri/ferrocyanide, validating the charge alteration with each successive polymer layer deposition. The studied deposition technologies can be used for the modification of TiN surfaces required in applications of this material in chemical sensors and other devices.}, language = {en} } @misc{BeisembekDimchevskaSazdovskaMirsky, author = {Beisembek, Alisher and Dimchevska Sazdovska, Simona and Mirsky, Vladimir M.}, title = {Separation of shifts in surface plasmon resonance into refractive index and thickness of deposited layers}, series = {Sensors and actuators. B, Chemical}, volume = {396}, journal = {Sensors and actuators. B, Chemical}, issn = {1873-3077}, doi = {10.1016/j.snb.2023.134606}, abstract = {Routine Surface Plasmon Resonance (SPR) measurements, which are widely applied in affinity (bio)sensors and surface science, do not allow one to separate the obtained SPR signals into the change of the refractive index and thickness of deposited layers. For thin layers the signal is proportional to the product of the layer thickness and the difference in the refractive indices of this layer and of the aqueous media. In this study, we suggest an approach to separate these parameters. It is performed by subsequent measurements in the presence and in the absence of polyethylene glycol (PEG), an inert additive which modifies the refractive index of the liquid phase but do not penetrate into the adsorbed layer. Both parameters were successively determined for human serum albumin (HSA) as well as for anti-HSA IgG in three different settings: i) HSA adsorbed directly onto a gold surface, ii) HSA chemically immobilized on a gold surface coated with a self-assembled monolayer of 1,16 mercaptohexadecanoic acid and iii) chemically immobilized HSA with additional monomolecular layer of anti- HSA IgG antibodies bond to this protein layer. The suggested approach can be applied in most SPR devices with a flow cell for analysis of various adsorbed layers.}, language = {en} } @misc{LaroussiRaouafiMirsky, author = {Laroussi, Arwa and Raouafi, Noureddine and Mirsky, Vladimir M.}, title = {Electrocatalytical Chemical Sensor for Hydrogen Peroxide}, series = {Engineering Proceedings}, volume = {6}, journal = {Engineering Proceedings}, number = {1}, issn = {2673-4591}, doi = {10.3390/I3S2021Dresden-10168}, abstract = {The fast and selective determination of hydrogen peroxide (H2O2) is of importance not only because of strong interest in this widely applied analyte, but also because of the development of enzymatic biosensors for glucose or other metabolites where the sensor for H2O2 can be used as the transducer. Here, we report on an electrocatalytical amperometric sensor for the detection of H2O2. It is a sensor that consists of a gold electrode covered by a self-assembled monolayer (SAM) with immobilized p-benzoquinone. To provide highly stable immobilization of p-benzoquinone at the distance of effective electron tunneling, a new anchor compound—1,3-dimercaptopropan-2-ol—was synthesized and used for preparation of the SAM. Due to two thiol groups binding gold surface, this compound provides high stability of the SAM. The surface concentration of p-benzoquinone obtained from cyclic voltammetry is 2.5 ± 0.2 × 10-10 mol·cm-2. Cyclic voltammetry and chronoamperometry experiments proved that the immobilized benzoquinone exhibited high electrocatalytic activity towards the decomposition of H2O2. Depending on the used potential range, different sensing modes can be realized. For example, one can measure electrochemical response due to the oxidation of H2O2 at anodic potentials, or due to the reduction of oxygen formed during oxidative decomposition of H2O2. Also, amperometric response at fixed potential of +0.4 V vs. Ag/AgCl corresponding to the oxidation of benzoquinone to hydroquinone was studied. The sensor exhibited a linear response over a concentration range of 0.1-2 mM with a low detection limit of 4.24 µM. The reproducibility of three different electrodes prepared was examined at the H2O2 concentration range from 0.1 till 3 mM, which resulted in a relative standard deviation below 4.2\%.}, language = {en} } @misc{EfremenkoMirsky, author = {Efremenko, Yulia and Mirsky, Vladimir M.}, title = {Chemosensitive properties of electrochemically synthesized poly-3-thienylboronic acid: conductometric detection of glucose and other diol-containing compounds under electrical affinity control}, series = {Polymers}, volume = {16}, journal = {Polymers}, number = {13}, publisher = {MDPI AG}, issn = {2073-4360}, doi = {10.3390/polym16131938}, abstract = {Due to the presence of the boronic acid moieties, poly-3-thienylboronic acid has an affinity for saccharides and other diol-containing compounds. Thin films of this novel chemosensitive polymer were synthesized electrochemically on the gold surface. The adhesion of the polymer was enhanced by the deposition of a monomolecular layer of thiophenol. The technology was used to fabricate conductometric sensors for glucose and other diol-containing compounds. Simultaneous two- and four-electrode conductivity measurements were performed. The chemical sensitivity to sorbitol, fructose, glucose, and ethylene glycol was studied at different pH and electrode potentials, and the corresponding binding constants were obtained. Depending on the electrode potential, the reciprocal values of the binding constants of glucose to poly-3-thienylboronic acid at neutral pH are in the range of 0.2 mM-1.0 mM. The affinity for glucose has been studied in buffer solutions and in solutions containing the major components of human blood. It was shown that the presence of human serum albumin increases the affinity of poly-3-thienylboronic acid for diol-containing compounds.}, language = {en} } @misc{SnopokNizamovSnopoketal., author = {Snopok, Borys A. and Nizamov, Shavkat and Snopok, Tetiana V. and Mirsky, Vladimir M.}, title = {Agglomeration compaction promotes corrosion of gold nanoparticles}, series = {Nanoscale Advances}, volume = {6}, journal = {Nanoscale Advances}, number = {15}, publisher = {Royal Society of Chemistry (RSC)}, issn = {2516-0230}, doi = {10.1039/D4NA00109E}, pages = {3865 -- 3877}, abstract = {Engineered nanoparticles are increasingly being used in various areas of human activity. However, the degradation mechanism of nanobodies in harsh environments is still a puzzle for theory and experiment. We report here the results of optical spectroscopy and nanoparticle tracking analysis, quantifying agglomeration and sizing of 50 nm citrate stabilized gold nanoparticles (GNPs) in HCl solutions containing H2O2. The mechanism of a consecutive corrosion reaction of GNPs is discussed within the framework of the near-field approach. We found that the disappearance of single nanoparticles from a suspension does not occur due to their dissolution per se, but is a consequence of the formation of aggregates. The neutralization of electrostatic shielding at high ionic strength allows gold nanoparticles to approach the subnanometer distance within the region of capping defects, at which the Casimir and van der Waals attractive forces dominate. It is suggested that electric field fluctuations in the confined space between highly conductive gold nanoparticles cause complexant-stimulated loss of metal from the core in the contact area. Going beyond the charge screening limitations by constraining the reaction space and reducing the double electrical layer thickness allows for chemical processes flow along otherwise not accessible reaction pathways.}, language = {en} } @misc{LaurinavichyuteNizamovMirsky, author = {Laurinavichyute, Veronika K. and Nizamov, Shavkat and Mirsky, Vladimir M.}, title = {Cyclic voltarefractometry of single TiO₂ nanoparticles in large ensembles in nonaqueous electrolyte}, series = {Analytical chemistry}, volume = {97}, journal = {Analytical chemistry}, number = {2}, publisher = {American Chemical Society}, address = {Washington, D.C.}, issn = {0003-2700}, doi = {10.1021/acs.analchem.4c04181}, pages = {1160 -- 1169}, abstract = {Single nanoparticle (NP) cyclic voltarefractometry (CVR), realized as wide-field surface plasmon resonance microscopy (SPRM) in combination with potential cycling, has been proposed and applied to the in situ study of TiO₂ NPs. Electrochemical activity of TiO₂ is mainly observed outside the electrochemical stability window of water. Therefore, the response of individual anatase (a-TiO₂) and rutile (r-TiO₂) NPs adsorbed on a gold layer was studied in 0.25 M LiClO4 acetonitrile solutions. The use of acetonitrile allows us to exploit a much wider potential window compared to water, while due to the almost identical refractive index (nD = 1.344 and 1.333 for acetonitrile and water, respectively), the conditions of the SPR are not changed. This greatly expands the variety of electrochemical reactions that can be studied by SPR techniques. Cyclic polarization of a-TiO₂ and r-TiO₂ NPs results in pronounced electrochemical and optical responses around -1.55 V and around -1.8 V vs Fc+/Fc, respectively. This specific optoelectrochemical response allows them to be distinguished from other NPs. Based on this difference in characteristic potentials, a mixture of a-TiO₂ and r-TiO₂ NPs can be analyzed by CVR as well. The proposed correction algorithm compensates for the drift in the SPRM background caused by the accompanying formation of insoluble compounds and separates the optical response of the NPs out of the background. The results obtained in the study of this complex system demonstrate the capabilities of the developed analytical method. The CVR can be applied to the quantitative analysis of many other types of NPs in nonaqueous solutions, providing information on the electrochemical properties of each individual particle on the electrode surface.}, language = {en} } @misc{SnopokDuckeMirsky, author = {Snopok, Borys A. and Ducke, Jana and Mirsky, Vladimir M.}, title = {Recognition of soft agglomerates in liquids : comparison and complementarity upon studying gold nanoparticles by tracking analysis, electron spectroscopy and microscopy}, series = {Powder technology}, volume = {468}, journal = {Powder technology}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {0032-5910}, doi = {10.1016/j.powtec.2025.121649}, pages = {1 -- 11}, abstract = {A key part of nanoscience is studying how tiny particles gather together in liquids. However, detecting soft agglomerates in their main population formed by single nanoparticles is challenging, since the pairing can only be revealed through adequate identification. In this study, we investigate the effects of agglomeration 60 nm citrate-stabilized gold by optical spectroscopy, nanoparticle tracking analysis and scanning electron microscopy. Optical spectroscopy is limited in its ability to detect soft agglomerates, indicating their presence only when the plasmonic band is approximated by profiles of different types. Electron microscopy requires optimisation of sampling protocols and substrate choice, but still reflects only the dominant agglomerates presented in suspension. Nanoparticle Tracking Analysis is the only method that allows us to characterise the agglomerates in their undistorted state, displaying their greatest diversity. However, it does not provide any information on their composition and shape. We have shown that a correct workflow leads to good agreement between all three methods with respect to the ratio of the most stable agglomerates and individual nanoparticles in the suspension. A detailed discussion of the observed correlations is presented, allowing us to identify gaps in the theoretical description important for the development of targeted analytical protocols.}, language = {en} } @misc{KayaEfremenkoMirsky, author = {Kaya, Berfinsu and Efremenko, Yulia and Mirsky, Vladimir M.}, title = {Conductometric chemosensor for saccharides based on thin films of poly(3-thienylboronic) acid : measurements of transversal resistance}, series = {Biosensors}, volume = {15}, journal = {Biosensors}, number = {10}, publisher = {MDPI AG}, address = {Basel}, issn = {2079-6374}, doi = {10.3390/bios15100679}, pages = {1 -- 15}, abstract = {Poly(3-thienylboronic acid) (PThBA) has recently been suggested as a conducting polymer with affinity for saccharides. In this study, thin films of this compound were deposited onto gold electrodes. The system obtained was studied as a possible chemical sensor. The measurements were performed by impedance spectroscopy using potassium ferro/ferricyanide as a redox mediator. The thickness of the polymer and the deposition of the adhesive sublayer were optimized to achieve a compromise between the blocking of defects in the polymer layer and the unnecessary increase in the internal resistance of this conductometric sensor. A comparative study of the influence of fructose, glucose, and sorbitol on transversal polymer resistance was conducted. The binding constants for these saccharides were extracted from the concentration dependencies of sensor conductance. Among them, sorbitol showed the highest affinity with a binding constant up to ~15,000 L·mol-1, followed by fructose (~8700 L·mol-1) and glucose (~4500 L·mol-1). In order to exclude the contribution of the analyte tautomers on the obtained binding constants, measurements of ethylene glycol were also performed. The effects of pH and the redox state of PThBA on its affinity properties were studied, revealing higher affinities at alkaline pH and in oxidized state of the chemosensitive polymer. The developed system has the capacity to be applied in chemical sensors and virtual sensor arrays with electrical affinity control.}, language = {en} } @misc{SenguelReiterLotfietal., author = {Seng{\"u}l, Akant and Reiter, Sebastian and Lotfi, Zahra and Efremenko, Julia and Laroussi, Arwa and Corley-Wiciak, Agnieszka Anna and Ratzke, Markus and Mirsky, Vladimir M. and Wenger, Christian and Fischer, Inga Anita}, title = {Titanium nitride plasmonic nanohole arrays with polymer coating : optical properties and their humidity-induced modifications}, series = {Optical materials express}, volume = {16}, journal = {Optical materials express}, number = {2}, publisher = {Optica Publishing Group}, address = {Washington, DC}, issn = {2159-3930}, doi = {10.1364/ome.578871}, pages = {184 -- 196}, abstract = {The use of titanium nitride (TiN) for the fabrication of plasmonic structures such as nanohole arrays (NHAs) can enable their integration into optoelectronic devices on the silicon (Si) platform, for example, for the realization of on-chip chemical sensors and biosensors based on refractometric transduction. With a corresponding functionalization of the TiN nanohole arrays, these ultra-compact devices can be utilized in the development of various affinity sensors and sensor systems, such as cost-effective electronic noses for the early detection of gases in the food industry or agriculture. In this work, we focus on two types of coating for functionalization of TiN nanohole arrays: electrochemically synthesized poly-N-methylaniline and layer-by-layer deposited polyacrylic-acid/poly-allylamine (PAA/PAH). Our investigation comprises the experimental characterization of the optical properties of TiN nanhole arrays coated with polymer layers of different thicknesses as well as a comparison with simulation results. We demonstrate the potential of our setup sensing applications by measuring changes in optical properties of TiN nanohole arrays coated with PAA/PAH upon exposure to air of different humidity.}, language = {en} }