Biosensor-based analysis

Huet AC, Fodey T, Haughey SA, Weigel S, Elliott C, Delahaut P. Advances in biosensor-based analysis for antimicrobial residues in foods. TrAC Trends Anal Chem 2010 29 1281-1294. 

Biosensor-based analysis is becoming more and more important in the food industry, and one of the fields of application is in vitamins analysis. The method for vitamin analysis is a label-free, inhibition assay (Kalman et al., 2006). The SPR biosensor monitors interactions of a specific binding protein with the vitamin immobilized on a CMS sensor chip. The prepared samples are mixed with a fixed concentration of the vitamin binding protein by the autosampler and injected over the chip surface. The vitamin present in the sample binds to the protein and subsequently inhibits it from binding to the surface of the sensor chip. The higher the concentration of the vitamin is in the sample, the higher the level of inhibition, and hence the lower the response of the biosensor (O Kane and Wahlstrom, 2011). A regeneration step prepares the chip surface for the next sample. Quantification is performed by multilevel caHbration with the vitamin standards. 

New natural polymers based on synthesis from renewable resources, improved recyclability based on retrosynthesis to reusable precursors, and molecular suicide switches to initiate biodegradation on demand are the exciting areas in polymer science. In the area of biomolecular materials, new materials for implants with improved durability and biocompatibility, light-harvesting materials based on biomimicry of photosynthetic systems, and biosensors for analysis and artificial enzymes for bioremediation will present the breakthrough opportunities. Finally, in the field of electronics and photonics, the new challenges are molecular switches, transistors, and other electronic components molecular photoad-dressable memory devices and ferroelectrics and ferromagnets based on nonmetals. 

Although the inhibition-based biosensors are sensitive, they are poor in selectivity and are rather slow and tedious since the analysis involves multiple steps of reaction such as measuring initial enzyme activity, incubation with inhibitor, measurement of residual activity, and regeneration and washing. Biosensors based on direct pesticide hydrolysis are more straightforward. The OPH hydrolyzes ester in a number of organophospho-rus pesticides (OPPs) and insecticides (e.g. paraoxon, parathion, coumaphos, diazinon) and chemical warfare agents (e.g. sarin) [53], For example, OP parathion hydrolyzes by the OPH to form p-nitrophenol, which can be measured by anodic oxidation. Rainina... 

B. Bucur, M. Dondoi, A. Danet, and J.L. Marty, Insecticide identification using a flow injection analysis system with biosensors based on various cholinesterases. Anal. Chim. Acta 539, 195-201 (2005). 

S. Milardovic, I. Kruhak, D. Ivekovic, V. Rumenjak, M. Tkalcec, and B.S. Grabaric, Glucose determination in blood samples using flow injection analysis and an amperometric biosensor based on glucose oxidase immobilized on hexacyanoferrate modified nickel electrode. Anal. Chim. Acta 350, 91-96... 

Karlsson R, Michaelsson A, Mattsson L. (1991) Kinetic analysis ofmonoclonal antibody-antigen interactions with a new biosensor based analytical system. J Immunol Methods 145,229-40. 

For these reasons, microbial sensors are less suitable for the determination of individual analytes. However, some practical apphcations for biosensors based on enzymes or antibodies for the specific determination of environmentally relevant compounds can be expected soon [11]. Furthermore, in some cases defined specific metabolic pathways in microorganisms are used, leading to microbial sensors for more selective analysis for those environmental pollutants which cannot be measured by the use of simple enzyme reactions, e.g., aromatic compounds and heavy metals. In this context it is also important to mention the aspect of bio availability, a parameter which is included by the measuring procedure of microbial sensors as an integral effect. 

The use of optical immune biosensors based on surface plasmon resonance (SPR) for the diagnostics of human and animal diseases as well as for environmental pollution monitoring, is one of prospective directions in biosensorics. The sensitivity of immune biosensors is similar to the ELIS A-method but the simphcity of obtaining results in the real time regime and the speed of the analysis are the main advantages of the biosensor approach. Performance of optical biosensors based on SPR depends on the state of the metallic surface as well as on the density, structure and the space volume of the immobilized molecules. It was demonstrated that the application of intermediate layers between the transducer surface and the sensitive biological molecules can optimize the working characteristics of the immune biosensor [7-14]. 

Further progress of ECL probes immobilization methods should result in new robust, stable, reproducible ECL sensors. Especially, the use of electrochemilumi-nescent polymers may prove to be useful in this respect. There are also good prospects for ECL to be used as detection in miniaturized analytical systems particularly with a large increase in the applications of ECL immunoassay because high sensitivity, low detection limit, and good selectivity. One can believe that miniaturized biosensors based on ECL technology will induce a revolution in clinical analysis because of short analysis time, low consumption of reactants, and ease of automation. 

M. Boujtita, J.P. Hart and R. Pittson, Development of a disposable ethanol biosensor based on a chemically modified screen-printed electrode coated with alcohol oxidase for the analysis of beer, Biosens. Bioelectron., 15(5-6) (2000) 257-263. 

P.A. Paredes, J. Parellada, V.M. Fernandez, I. Katakis and E. Dominguez, Amperometric mediated carbon paste biosensor based on D-fructose dehydrogenase for the determination of fructose in food analysis, Biosens. Bioelectron., 12(12) (1998) 1233-1243. 

Electrochemical biosensors based on vegetable tissues and crude extracts for environmental, food and pharmaceutical analysis... 

DNA biosensors based on GEC meet the demands of genetic analysis, especially in food, biotechnology and pharmaceutical industries, while also generating new possibilities for the development of DNA biosensors that are sensitive, robust, low cost and easily produced. 

Table 23.5 summarises the main features of papers which detail experimental approaches to the analysis of amino acids, peptides and proteins (other than hormones) using electrochemical biosensor-based methodologies involving SPCEs. 

However, it should be mentioned that there is a flexible hand-held electrochemical instrument on the market, which can be programmed to be used in a variety of voltammetric/amperometric modes in the field [209]. Although the majority of biosensor applications described in this review were for single analyte detection, it is very likely that future directions will involve development of biosensor arrays for multi-analyte determinations. One example of this approach has been described in an earlier section, where five OPs could be monitored with an array of biosensors based on mutant forms of AChE from D. melanogaster [187]. This array has considerable potential for monitoring the quality of food, such as wheat and fruit. Developments and applications of biosensors in the area of food analysis are expected to grow as consumer demand for improved quality and safety increases. Another area where biosensor developments are likely to increase significantly is in the field of environmental analysis, particularly with respect to the defence of public... 

E. Crouch, D.C. Cowell, S. Hoskins, R.W. Pittson and J.P. Hart, Amperometric, screen-printed, glucose biosensor for analysis of human plasma samples using a biocomposite water-based carbon ink incorporating glucose oxidase, Anal. Biochem., 347 (2005) 17-23. 

DNA biosensors, based on the summarized schemes, have been proposed in different area of analysis environmental, clinical, food control, biotechnology, and pharmaceutical. 

G. Panayotou, G. Gish, P. End, O. Truong, I. Gout, R. Dhand, et al. Interactions between SH2 domains and tyrosine-phosphorylated platelet-derived growth fector beta-receptor sequences analysis of kinetic parameters by a novel biosensor-based approach. Mol Cell Biol, 13 (6), 3567-3576, 1993. 

Simoni P, Baraldini M. Bioluminescent biosensors based on 60. genetically engineered living cells in environmental and food analysis. Analytical Lett. 2006 39 1503-1515. 

Dextran hydrogels have been successfully applied in biosensors based on surface plasmon resonance. Carboxymethyl-dextran (CM-dextran) hydrogel was the original sensor surface developed for biomolecular interaction analysis and hence the most extensively studied and versatile. It has been used in a very wide range of interaction analyses including those between proteins, nucleic acids, and carbohydrates [40,41]. 

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