Filtern
Dokumenttyp
- Posterpräsentation (5)
- Zeitschriftenartikel (2)
- Vortrag (2)
- Buchkapitel (1)
- Beitrag zu einem Tagungsband (1)
Referierte Publikation
- nein (11) (entfernen)
Schlagworte
- Fluorescence (2)
- Chromatography (1)
- Core-shell nanoparticles (1)
- Dyes (1)
- Enantioselectivity (1)
- Enantioselektivität (1)
- Fluoreszenz (1)
- Kern-Schale-Partikel (1)
- Molecular imprinted polymers (1)
- Molecular imprinting (1)
Organisationseinheit der BAM
Eingeladener Vortrag
- nein (2)
Direct Anion Sensing with Amplified Flourescence Using Moleculary Imprinted Core-Shell Nanoparticles
(2013)
Integration of a polymerisable fluorescent urea-nitrobenzoxadiazole monomer 1 into a few-nanometre thin molecularly imprinted polymer (MIP) shell coated onto a 300 nm silica core with the tetrabutylammonium salt of N-carbobenzyloxy-L-phenylalanine (Cbz- or Z-ʟ-Phe) as the imprinted template yields core/shell MIP nanoparticles that respond to the designated analyte with a strong fluorescence increase in the visible spectral range. The system shows promising imprinting and enantioselectivity factors of 3.6 and 1.9 when benzylmethylacrylate (BMA) is used as co-monomer and ethylene glycol dimethacrylate (EDMA) as cross-linker. A second, naphthalimide-based fluorescent urea 2 is employed in the preparation of MIP thin-films and monolithic polymers for separation techniques. Spectroscopic and chromatographic studies of the MIPs with the analytes Z-ʟ-Phe, Z-ʟ-glutamic acid (Z-ʟ-Glu) and penicilin G (PenG) revealed the (enantio)selective discrimination behaviour of these materials.
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.
An ideal sensor system is a combination of a selective receptor, an effective transducer, and a sensitive detector. To utilize molecularly imprinted polymers (MIPs) as responsive recognition phases in sensors, the employment of fluorescent molecules or nanoparticles (NPs) that show prominent changes in their spectroscopic properties after binding of the target molecule in the MIP’s cavity is particularly attractive. Such fluorescent MIPs (fMIPs) act through target-induced quenching, enhancement, or spectral shifts of the fluorescence. This contribution introduces different strategies of incorporation of fluorescent dyes, probes, and NPs into fMIPs. In addition, various sensing mechanisms are reviewed, and depending on the application of the sensor, the different deployable formats, their advantages, drawbacks, and impact will be presented and discussed.
Use fluorogenic Molecularly imprinted particles to detect phosphate anion on the microfluidic chips
(2015)
The exploration of new material and technique in the past half century has greatly improved our life quality but also brings threats like environmental pollution and desease. The monitoring of these harmful species is especially important for us human being and the planet we live. However, the traditional laboratory based assay is a complicate process including sample preparation, detection and data analysis. The onsite detection as well as point of care (POC) diagnostic are often limited by the dimension of large instrument and required trained people. In order to address these problems, we combined the sensor particle with the microfluidic chip technique for the potential miniaturized direct readout sensor instrument for onsite detection.
MIPs are artificial receptors which are formed by polymerization of functional monomer at the presence of target molecule as template. They have comparable binding affinity and selectivity to the nature receptor such as anbibody and enzyme. However they are more stable and robust which greatly reduced the difficulty in storage and usage. The thermal and chemical stability also extends its application to more harsh conditions. Combined with core coding technique, they can also combine with fluidic assay for much higher throughout. We have developed a fluorogenic sensor particle which is formed by a thin fluorogenic molecularly imprinted polymer (fMIPs) shell of several nanometer coated onto a silica particle as core-substrate. These particles can respond to the molecule such as phosphorylated tyrosine through change of fluorescence signals and show high selectivity, sensitivity and fast response within 20 seconds. The phosphate anion is especially interesting due to its important role in industry as well as in biological processes.
In order to make it applicable for on-site monitoring, we combined this fMIPs with a microfluidic chips. With carefully design, the particle can essentially mixed with the sample in the microfluidic chip. The excitation of sensor particle can be enabled by a LED, the fluorescence difference can then directly been registered with a spectrometer for qualification as well quantification the monitored species. The compact structure make the on-site as well as POC achievable.