Electrochemical biosensors, polymeric membranes

Electrochemical sensor fabrication has dominated the analytical application of polymers. In some sensors the polymer film acts as a membrane for the preconcentration of ions or elements before electrochemical detection. Polymers also serve as materials for electrode modification that lower the potential for detecting analytes. In addition, some polymer films function as electrocatalytic surfaces. Using a polymer in biosensors is a very rapidly developing area of electroanalytical chemistry. Polymeric matrix modifiers have been applied as diffusional barriers in constructing not only sensitive amperometric biosensors, but also electrochemical sensors that apply potentiometric, conductimetric, optical, and gas-sensing transducer systems. The principles, operations, and application of potentiometric, conductimetric, optical and gas sensors are described in Refs. 13, 39-41. In this chapter, we focus mainly on amperometric biosensors based on redox enzymes. 

Electrochemical polymerization (electropolymerization) has been recognized as a useful technique for the preparation of pinhole-fiee membranes (1,2) that have found numerous applications in electrocatalysis, amperometric biosensors, etc. These membranes are prepared by the electrodeposition of a polymeric film on the surface of an electrode that is immer in a solution of an appropriate monomer. In order for polymerization to occur, groups that can be electrochemically oxidized or reduced to form a polymer need to be present in the monomer. 

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