Plasma-polymerized films for biosensors

A biosensor is a useful tool for chemical, biochemical, medical and environ mental fields because of its compact size, real time analysis, nearly reage ntless operation, simple pretreatment protocols and simplicity of use. The performance of the biosensor often depends on how well the biological compo nents are combined to the transducers, which is also referred to as 'immobi lization of biological components' or 'interfacial design'. A plasma-polyme rized film, achieved in glow discharge or plasma in vapor phase, offers a n ew alternative for use in the interfacial design of the biosensors. The pro perties of the film are that they (i) are extremely thin (<1 mu m), (ii) pr ovide good adhesion to the substrate, (iii) are pin-hole free and present a flat surface structure, (iv) are mechanically and chemically stable becaus e of the highly branched and cross-linked structure in the polymer, and (v) allow for a large amount of biological components such as enzymes and anti bodies to be loaded onto the surface of the film because of its biocompatib le characteristics. The films have potential for use in the interfacial des ign for biosensors from both a fundamental and a practical aspect. In this article, we review the usefulness of plasma-polymerized films as interfaces in biosensing applications. (C) 1999 Elsevier Science B.V. All rights rese rved.