Optical enzyme-based sensors methods

Hale Z M and Payne F P 1994 Fluorescent sensors based on tapered single-mode optical fibres Sensors Actuators 17 233 0 Luo S and Walt D R 1989 Avidin-biotin coupling as a general method for preparing enzyme-based fiber-optic sensors Anal. Chem. 61 1069-72 Li L and Walt D R 1995 Dual-analyte fiber-optic sensor for the simultaneous and continuous measurement of glucose and oxygen Anal. Chem. 67 3746-52 Tan W, Shi Z-Y, Smith S, Bimbaum D and Kopelman R 1992 Submicrometer intracellular chemical optical fiber sensors Science 258 778-81 Tan W, Shi Z-Y and Kopelman R 1992 Development of submicron chemical fiber optic sensors Anal. Chem. 64 2985-90... 

Luo, S., Walt, D. R., Avidin-Biotin Coupling as a General Method for Preparing Enzyme-Based Fiber-Optic Sensors , Anal. Chem. 61 (1989) 1069-1072. 

Luo. S. Walt, D.R. Avidin-biotin coupling as a general method for preparing enzyme-based fiber-optic sensors. Anal. Chem. 1989. 61. 1069. 

A review of chemical sensors and arrays [6] focuses on conducting polymers as inherent receptors, the modification of conducting polymers with receptors, the use of conducting polymers as transducers as well as some applications in combinatorial and high-throughput assays. Fundamental aspects of redox-related conductivity and pH-sensitive conductivity are included, and applications to chemical- and enzyme-based biosensors are summarized based on analyte. A variety of detection methods (electrical, electrochemical, and optical) are surveyed. 

Based on many of the advances described above in electrochemical approaches to immunoassay, it is tempting to conclude that commercialization of some of the approaches is imminent. This may be true, but the historical use of optical methods for many clinical chemistry tests coupled with their rapidly growing use in immunoassay is a difficult barrier for any radically different method to overcome, though electrochemical sensors have become more important in the clinical chemistry laboratory over the last decade. In any event, to be successful ECIA methods will have to demonstrate clear superiority over existing and emerging technologies in both cost and performance. Some of the more recently described approaches such as those using enzyme amplified amperometric detection and ecLIA appear... 

In this part we will describe recent achievements in the development of biosensors based on DNA/RNA aptamers. These biosensors are usually prepared by immobilization of aptamer onto a solid support by various methods using chemisorption (aptamer is modified by thiol group) or by avidin-biotin technology (aptamer is modified by biotin) or by covalent attachment of amino group-labeled aptamer to a surface of self-assembly monolayer of 11-mercaptoundecanoic acid (11-MUA). Apart from the method of aptamer immobilization, the biosensors differ in the signal generation. To date, most extensively studied were the biosensors based on optical methods (fluorescence, SPR) and acoustic sensors based mostly on thickness shear mode (TSM) method. However, recently several investigators reported electrochemical sensors based on enzyme-labeled aptamers, electrochemical indicators and impedance spectroscopy methods of detection. 

This volume presents a cross section of recent advances in the development of novel chemical and biochemical sensors for on-line monitoring and control applications in the environmental, clinical, and bioprocess areas. These chapters illustrate how many of the key challenges for continuous monitoring are being addressed. The methods discussed include optical techniques ranging from near-infrared spectroscopy to lifetime-based phase fluorometry biosensors ranging from optical immu-nosensors to enzyme-electrodes as well as electrochemical, acoustic, and plasmon resonance techniques. 

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