Biosensors miniaturized

Miniaturization and mass production of biosensors could increase their availability and decrease their unit cost. Technologies such as microlithography, ultrathin membranes, and molecular self-assembly have the potential to facilitate the development and diversification a wide variety of biosensors. Miniature biosensors could be incorporated into food packages to monitor temperature stress, microbial contamination, or remaining shelf life, and to provide a visual indicator to consumers of product state at the time of purchase (3,51,52). 

The current trend in analytical chemistry applied to evaluate food quality and safety leans toward user-friendly miniaturized instruments and laboratory-on-a-chip applications. The techniques applied to direct screening of colorants in a food matrix include chemical microscopy, a spatial representation of chemical information from complex aggregates inside tissue matrices, biosensor-based screening, and molec-ularly imprinted polymer-based methods that serve as chemical alternatives to the use of immunosensors. 

Enzyme-based optical sensor applications will be further described in this book. They are still the most widespread optical biosensors but work is needed to overcome limitations such as shelf life, long term stability, in situ measurements, miniaturization, and the marketing of competitive devices. 

L. Mao, E Xu, Q. Xu, and L. Jin, Miniaturized amperometric biosensor based on xanthine oxidase for monitoring hypoxanthine in cell culture media. Anal. Biochem. 292, 94—101 (2001). 

S.A. Jaffari and J.C. Pickup, Novel hexacyanoferrate(III)-modified carbon electrodes application in miniaturized biosensors with potential for in vivo glucose sensing. Biosens. Bioelect. 11, 1167—1175... 

Zhang, Y. Shibru, H. Cooper, K. L. Wang, A., Miniature fiber optic multicavity Fabry Perot interferometric biosensor, Opt. Lett. 2005, 30, 1021 1023... 

Field effect transistors are miniature, solid-state, potentiometric transducers (Figure 4.22) which can be readily mass produced. This makes them ideal for use as components in inexpensive, disposable biosensors and various types are being developed. The function of these semiconductor devices is based on the fact that when an ion is absorbed at the surface of the gate insulator (oxide) a corresponding charge will add at the semiconductor... 

Strongly enhanced capabilities of chemically modified IR fibre optics for use in miniature biosensors. 

Meeusen, C. A., Alocilja, E. C., and Osburn, W. N. (2005). Detection of E. coli 0157 H7 using a miniaturized surface plasmon resonance biosensor. Trans. ASAE 48, 2409-2416. 

As an outlook, the optimization of the efficiency of microorganisms with methods of genetic engineering will result in an increased sensitivity, selectivity, and stability, in connection with the further miniaturization of biosensor systems, especially the development of portable biosensor measuring devices, represents a promising feature for environmental monitoring by microbial... 

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. 

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