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Rapid pathogen detection is an emerging issue in clinical, environmental, and food industry sectors. Biosensors can represent a solution to culture-based and molecular methods as they respond to sensitivity, specificity, and rapidity needs. Screen-printed electrodes have been used in association with nanoparticles to increase the signal and improve sensitivity reaching low numbers of the targets. Antibodies, DNA probes, and aptamers are mainly used to functionalize the working electrodes to ensure high specific pathogen detection by the use of voltammetry, impedance spectroscopy, amperometry, and conductivity. Electrochemical biosensors can be miniaturized to construct portable devices useful for in situ assays. 相似文献
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Electroanalytical biosensors and their potential for food pathogen and toxin detection 总被引:1,自引:0,他引:1
The detection and identification of foodborne pathogens continue to rely on conventional culturing techniques. These are very
elaborate, time-consuming, and have to be completed in a microbiology laboratory and are therefore not suitable for on-site
monitoring. The need for a more rapid, reliable, specific, and sensitive method of detecting a target analyte, at low cost,
is the focus of a great deal of research. Biosensor technology has the potential to speed up the detection, increase specificity
and sensitivity, enable high-throughput analysis, and to be used for monitoring of critical control points in food production.
This article reviews food pathogen detection methods based on electrochemical biosensors, specifically amperometric, potentiometric,
and impedimetric biosensors. The underlying principles and application of these biosensors are discussed with special emphasis
on new biorecognition elements, nanomaterials, and lab on a chip technology. 相似文献
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Screening serum for the presence of prostate specific antigen (PSA) belongs to the most common approach for the detection of prostate cancer. This review (with 156 refs.) addresses recent developments in PSA detection based on the use of various kinds of nanomaterials. It starts with an introduction into the field, the significance of testing for PSA, and on current limitations. A first main section treats electrochemical biosensors for PSA, with subsections on methods based on the use of gold electrodes, graphene or graphene-oxide, carbon nanotubes, hybrid nanoparticles, and other types of nanoparticles. It also covers electrochemical methods based on the enzyme-like activity of PSA, on DNA-, aptamer- and biofuel cell-based methods, and on the detection of PSA via its glycan part. The next main section covers optical biosensors, with subsections on methods making use of surface plasmon resonance (SPR), localized SPR and plasmonic ELISA-like schemes. This is followed by subsections on methods based on the use of fiber optics, fluorescence, chemiluminescence, Raman scattering and SERS, electrochemiluminescence and cantilever-based methods. The most sensitive biosensors are the electrochemical ones, with lowest limits of detection (down to attomolar concentrations), followed by mass cantilever sensing and electrochemilumenescent strategies. Optical biosensors show lower performance, but are still more sensitive compared to standard ELISA. The most commonly applied nanomaterials are metal and carbon-based ones and their hybrid composites used for different amplification strategies. The most attractive sensing schemes are summarized in a Table. The review ends with a section on conclusions and perspectives. 相似文献
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DNA biosensors (or genosensors) are analytical devices that result from the integration of a sequence-specific probe and a signal transducer. Among other techniques, electrochemical and piezoelectric methods have recently emerged as the most attractive due to their simplicity, low instrumentation costs, possibility for real-time and label-free detection and generally high sensitivity.Focusing on the most recent activity of worldwide researchers, the aim of the present review is to give the readers a critical overview of some important aspects that contribute in creating successful genosensing devices. Advantages and disadvantages of different sensing materials, probe immobilisation chemistries, hybridisation conditions, transducing principles and amplification strategies will be discussed in detail. Dedicated sections will also address the issues of probe design and real samples pre-treatment. Special emphasis will be finally given to those protocols that, being implemented into an array format, are already penetrating the molecular diagnostics market. 相似文献
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Wei Q Seward GK Hill PA Patton B Dimitrov IE Kuzma NN Dmochowski IJ 《Journal of the American Chemical Society》2006,128(40):13274-13283
Xenon-129 biosensors offer an attractive alternative to conventional MRI contrast agents due to the chemical shift sensitivity and large nuclear magnetic signal of hyperpolarized (129)Xe. Here, we report the first enzyme-responsive (129)Xe NMR biosensor. This compound was synthesized in 13 steps by attaching the consensus peptide substrate for matrix metalloproteinase-7 (MMP-7), an enzyme that is upregulated in many cancers, to the xenon-binding organic cage, cryptophane-A. The final coupling step was achieved on solid support in 80-92% yield via a copper (I)-catalyzed [3+2] cycloaddition. In vitro enzymatic cleavage assays were monitored by HPLC and fluorescence spectroscopy. The biosensor was determined to be an excellent substrate for MMP-7 (K(M) = 43 microM, V(max) = 1.3 x 10(-)(8) M s(-1), k(cat)/K(M) = 7,200 M(-1) s(-1)). Enzymatic cleavage of the tryptophan-containing peptide led to a dramatic decrease in Trp fluorescence, lambda(max) = 358 nm. Stern-Volmer analysis gave an association constant of 9000 +/- 1,000 M(-1) at 298 K between the cage and Trp-containing hexapeptide under enzymatic assay conditions. Most promisingly, (129)Xe NMR spectroscopy distinguished between the intact and cleaved biosensors with a 0.5 ppm difference in chemical shift. This difference most likely reflected a change in the electrostatic environment of (129)Xe, caused by the cleavage of three positively charged residues from the C-terminus. This work provides guidelines for the design and application of new enzyme-responsive (129)Xe NMR biosensors. 相似文献
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Cell-based impedance biosensing is an emerging technology that can be used to non-invasively and instantaneously detect and analyze cell responses to chemical and biological agents. This article highlights the fabrication and measurement technologies of cell impedance sensors, and their application in toxin detection and anti-cancer drug screening. We start with an introduction that describes the capability and advantages of cell-based sensors over conventional sensing technology, followed by a discussion of the influence of cell adhesion, spreading and viability during cell patterning on the subsequent impedance measurements and sensing applications. We then present an electronic circuit that models the cell-electrode system, by which the cellular changes can be detected in terms of impedance changes of the circuit. Finally, we discuss the current status on using cell impedance sensors for toxin detection and anti-cancer drug screening. 相似文献
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Aptamer-based biosensors for the detection of HIV-1 Tat protein 总被引:7,自引:0,他引:7
Tombelli S Minunni M Luzi E Mascini M 《Bioelectrochemistry (Amsterdam, Netherlands)》2005,67(2):135-141
Two biosensors have been constructed using an RNA aptamer as biorecognition element. The aptamer, specific for HIV-1 Tat protein, has been immobilised on the gold surface of piezoelectric quartz crystals or surface plasmon resonance (SPR) chips to develop a quartz crystal microbalance (QCM)-based and an SPR-based biosensor, respectively. Both the biosensors were modified with the same immobilisation chemistry based on the binding of a biotinylated aptamer on a layer of streptavidin. The binding between the immobilised aptamer and its specific protein has been evaluated with the two biosensors in terms of sensitivity, reproducibility and selectivity. A protein very similar to Tat, Rev protein, has been used as negative control. The two biosensors both were very reproducible in the immobilisation and the binding steps. The selectivity was high in both cases. 相似文献
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This article provides a review of the published literature describing the use of biosensors and biologically-inspired systems for explosives detection. The review focusses on the use of antibodies, enzymes, biologically-inspired synthetic ligands and whole-cell biosensors, providing a flavour of the range of technology, formats and approaches that can be used to detect explosives using biological systems. 相似文献
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Organophosphorus (OP) pesticides can be rapidly detected by integrating organophosphorus hydrolase with an optical leaky waveguide biosensor. This enzyme catalyses the hydrolysis of a wide range of organophosphorus compounds causing an increase in the pH. Thus, the direct detection of OP is possible by monitoring of the pH changes associated with the enzyme's activity. This article describes the use of an optical, leaky waveguide clad with absorbing materials for the detection of OP pesticides by measuring changes in refractive index, absorbance and fluorescence. In the most effective configuration, a thick sensing layer was used to increase the amount of immobilized enzyme and to increase the light interaction with the sensing layer, resulting in a greatly enhanced sensitivity. The platforms developed in this work were successfully used to detect paraoxon and parathion down to 4 nM concentrations. 相似文献
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Rapid on-site detection of pathogenic bacteria with high sensitivity and specificity is becoming an urgent need in public health assurance, medical diagnostics, environmental monitoring, and food safety fields. Despite being reliable and widely used, the existing methods of bacteria detection are cumbersome and time-consuming, which is not conducive to field detection. Microfluidic lab-on-a-chip technology has provided a detective tool for various analytes, due to its miniaturization, portabilit... 相似文献
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Oczkowski T Zwierkowska E Bartkowiak S 《Bioelectrochemistry (Amsterdam, Netherlands)》2007,70(1):192-197
Cell-based biosensors, bioelectronic portable devices containing plant living cells have been used for monitoring some physiological changes induced by pathogen-derived signal molecules called flagellin. The screen-printed electrodes have been adapted for preparation of biosensors. The proton-sensitive thick films have been printed using composite bulk modified with edition of RuO(2). Obtained disposable electrodes were made possible to measure the pH change with well sensitivity and reproducibility. Tobacco cells attached to the electrode surface, cell-based biosensor, can be used for the detection of flagellin, the virulence factor of bacterial pathogen. We culture tobacco cells on the surface of such electrotransducer for several weeks and monitor of potential of cells under flagellin stimulation. The detection of the electrochemical proton gradient across the plasma membrane serves as the analytical signal. The electrode response depended upon H(+) concentration in extracellular solution. It can be conveniently observed on the surfaces of biosensors. Suitable stability and the good response time of constructed biosensors were observed. Future development of these cell-based biosensors could draw advances in selective monitoring of microbial pathogens and other physiologically active components. Moreover, this new method is much faster compared with the traditional microbial testing. 相似文献
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Early and precise diagnosis are propitious to timely treatment and simultaneously increase the chance of successful treatments. It is of critical importance to develop rapid, sensitive, and reliable sensing techniques of physiological biomarkers for disease diagnosis. Due to the advantages of structural designability and property tunability, nanoscale metal-organic frameworks(nMOFs) have been widely applied in the field of biomedicine in recent years. Particularly, enhanced stability, more modif... 相似文献
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Baeumner A 《Analytical and bioanalytical chemistry》2008,391(2):449-450
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Recent successful syntheses of monodispersed magnetic nanoparticles have offered a unique opportunity to control and probe biological interactions using magnetic force. This paper highlights a general strategy to generate biofunctional magnetic nanoparticles, illustrates applications for these nanoparticles in protein separation and pathogen detection, and analyzes the high sensitivity and high selectivity achieved by this system. 相似文献