Biosensors transducers

J. Min and A.J. Baeumner, Characterization and optimization of interdigitated ultramicroelectrode arrays as electrochemical biosensor transducers. Electroanalysis 16, 724—729 (2004). 

Due to their advantages over conventional optical arrays, electronic biosensor transducers and arrays have attracted intensive research interest in recent years. The vast majority of those efforts, however, are focused on the use of FETs as transducers and only a few groups have successfully prototyped their array devices [46-54]. The obvious reason for this is the high cost of mask making and chip fabrication. Among them, the CMOS process dominates due to the easy access to commercial CMOS foundries. 

Cevik, S., Timur, S., Anik, U., 2013. Poly(allylamine hydrochloride) functionalized multiwalled carbon nanotube modified carbon paste electrode as acetylcholinesterase biosensor transducer. Electroanalysis 25 (10), 2377-2383. 

Martinez-Eabregas, E. Alegret, S. A Practical Approach to Ghemical Sensors through Potentiometric Transducers Determination of Urea in Serum by Means of a Biosensor, /. Chem. Educ. 1994, 71, A67-A70. 

Fig. 8. Basic components of a biosensor. In the case of an immunosensor, the antibody (or antigen) would be immobilized onto the transducer.

The simple cases where one enzyme is employed afford a limited scope of potential targets. Usually two or more enzyme reactions are coupled, as exemplified by the development of a piezoelectricaHy-transduced biocatalytic biosensor that couples two enzyme reactions to detect glucose [492-62-6] ... 

The immobilization of the hyperbranched spherical structures onto physical transducers greatly increases the binding capacity of the surface and leads to enhanced sensitivity and extended linearity of biosensors. Nucleic acid dendrimers were prepared and their amplification properties for the detection of DNA were examined using mass-sensitive transducers [45, 46]. Antibodies... 

Biosensors may provide the basis for in-field analyses and real-time process analysis. However, biosensors are generally limited to the determination of a limited range of analytes in defined matrices. Enzyme-based biosensors, principally acetylcholinesterase (AChE) inhibition, have been successfully used in environmental analysis for residues of dichlorvos and paraoxon, " carbaryl " and carbofuran. " Immunochemically based biosensors may be the basis for the determination of pesticide residues in liquid samples, principally water and environmental samples, but also fruit juices. The sensors can be linked to transducers, for example based on a piezo-... 

The initial hurdle to overcome in the biosensor application of a nucleic acid is that involving its stable attachment on a transducing element which commonly includes a metallic electrode. In the first part of this chapter, we wish to introduce our approach for DNA immobilization (Scheme 1). A detailed characterization of the immobilization chemistry is also presented. In the second part, we follow the development of work from our laboratory on chemical sensor applications of the DNA-modified electrode involving a biosensor for DNA-binding molecules and an electrochemical gene sensor. 

Table 3. Early optical enzyme-based biosensors, and respective transducers (work published until 1992). Data on work by Schaffar Wolfbeis from ref. 130. For a recent review see ref. (131).

Trettnak W., Wolfbeis O.S., Fiber optic cholesterol biosensor with an oxygen optrode as the transducer Anal. Biochem. 1990 184 124. 

Trettnak W., Leiner M.J.P., Wolfbeis O.S., Fibre-optic glucose sensor with a pH optrode as a transducer, Biosensors 1988 4 15. 

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