biosensor
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Biosensors using cholinesterases as the biorecognition component have been used to assay organophosphates and carbamates for a long time. In this review, some strategies convenient for biosensor construction are presented. Solutions for cholinesterase immobilization and output signal monitoring are presented as the basic presumptions for successful biosensor construction.
- MeSH
- biosenzitivní techniky metody MeSH
- cholinesterasy metabolismus MeSH
- enzymy imobilizované metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- přehledy MeSH
We present a compact surface plasmon resonance (SPR) biosensor for the detection of bisphenol A (BpA), an endocrine-disrupting chemical. The biosensor is based on an SPR sensor platform (SPRCD) and the binding inhibition detection format. The detection of BpA in PBS and wastewater was performed at concentrations ranging from 0.05 to 1,000 ng/ml. The limit of detection for BpA in PBS and wastewater was estimated to be 0.08 and 0.14 ng/ml, respectively. It was also demonstrated that the biosensor can be regenerated for repeated use. Results achieved with the SPR biosensor are compared with those obtained using ELISA and HPLC methods.
Procalcitonin is a blood protein and precursor of the hormone calcitonin. The procalcitonin level increases due to bacterial infections, sepsis, and other related pathologies. Here, we present a simple biosensor for procalcitonin assay suitable for point-of-care tests as an alternative to the current laboratory methods. The biosensor was based on a QCM piezoelectric sensor and a conjugate of gold nanoparticles-antibodies conjugate. It was suitable for the procalcitonin assay in biological samples and fully correlated to the standard ELISA method, and it did not suffer false positive or negative results or interferences. The detection limit was equal to 37.8 ng/l and the quantification limit to 104 ng/l for a sample of 25 μl. The dynamic range of the assay was 37.8 ng/l to 30.0 μg/l. The practical relevance of the biosensor is expected considering the findings, and the possible application of the assay principle for the development of biosensors for other markers is inferred.
The principle of synchronous detection (SD) has been applied to biosensor measurement. SD principle achieves significant increases in the signal to noise ratio, limit of detection and overall measurement robustness. Application of SD in biosensor measurement improves the analysis of the response and avoids the influence of interference/noise produced by stirring, electromagnetic effects and influence of parasitic currents. SD also enables the decomposition of signal to stimulation response and phenomena with long time of response. Second-order phenomena are identifiable in the signal. Linear statistical model was used to develop software for identification of the stimulation signal in the output current. SD was applied to the response signal of a Photosystem II complex (PSII) biosensor. PSII response to light stimulation follows first order kinetics. The inhibition kinetics of PSII has been studied. Kinetic constants of herbicide binding to PSII depend linearly on herbicide concentration and enable measurement of its concentration at low concentrations (linear range for diuron is 10⁻⁶ to 10⁻⁴ mM).
- MeSH
- biosenzitivní techniky metody MeSH
- časové faktory MeSH
- enzymy imobilizované antagonisté a inhibitory metabolismus MeSH
- fotosystém II (proteinový komplex) antagonisté a inhibitory metabolismus MeSH
- inhibitory enzymů farmakologie MeSH
- kinetika MeSH
- Synechococcus enzymologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Interferon gamma (IFNγ) is a cytokine and an immunochemical marker that can be used for revealing of infectious diseases and especially for distinguishing of viral and some types of bacterial infections. Blood tests for IFNγ are typically based on immunoassays like Enzyme-Linked Immunosorbent Assay (ELISA). In this paper, a biosensor working on the principle of quartz crystal microbalance (QCM) was developed as an alternative to the standard analytical methods for IFNγ. The biosensor contained antibodies against IFNγ immobilized on QCM and also on gold nanoparticles. A sandwich containing QCM, gold nanoparticles and IFNγ was formed and formation of the sandwich caused decrease of oscillation frequency. The assay exerted limit of detection 5.7 pg/ml for a sample sized 50 μl and one measuring cycle was finished within 90 min. The assay by biosensor fully correlated to standard ELISA. In a conclusion, the biosensor appears to be a fully applicable analytical tool for a simple assay of IFNγ. Overall simplicity and no special requirement on staff and equipment are the major advantages of the here presented assay.
- MeSH
- biosenzitivní techniky * MeSH
- imunoanalýza MeSH
- interferon gama MeSH
- kovové nanočástice * MeSH
- křemen MeSH
- lidé MeSH
- mikrorovnovážné techniky křemenného krystalu MeSH
- zlato MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
An ultrasensitive impedimetric glycan-based biosensor for reliable and selective detection of inactivated, but intact influenza viruses H3N2 was developed. Such glycan-based approach has a distinct advantage over antibody-based detection of influenza viruses since glycans are natural viral receptors with a possibility to selectively distinguish between potentially pathogenic influenza subtypes by the glycan-based biosensors. Build-up of the biosensor was carefully optimized with atomic force microscopy applied for visualization of the biosensor surface after binding of viruses with the topology of an individual viral particle H3N2 analyzed. The glycan biosensor could detect a glycan binding lectin with a limit of detection (LOD) of 5 aM. The biosensor was finally applied for analysis of influenza viruses H3N2 with LOD of 13 viral particles in 1 μl, what is the lowest LOD for analysis of influenza viral particles by the glycan-based device achieved so far. The biosensor could detect H3N2 viruses selectively with a sensitivity ratio of 30 over influenza viruses H7N7. The impedimetric biosensor presented here is the most sensitive glycan-based device for detection of influenza viruses and among the most sensitive antibody or aptamer based biosensor devices.
- MeSH
- biosenzitivní techniky metody MeSH
- chřipka lidská diagnóza virologie MeSH
- impedanční spektroskopie metody MeSH
- lidé MeSH
- limita detekce MeSH
- polysacharidy chemie MeSH
- virus chřipky A, podtyp H3N2 izolace a purifikace MeSH
- virus chřipky A, podtyp H7N7 izolace a purifikace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
