Enzyme sensors prepared by layer-by-layer deposition of enzymes on a platinum electrode through avidin-biotin interaction

An alternate and repeated deposition of avidin and biotin-labeled glucose o xidase (GOx) or lactate oxidase (LOx) on a solid surface gave protein multi layers through a strong binding between avidin and biotin. Spectrophotometr ic and gravimetric techniques using UV absorption and a quartz-crystal micr obalance revealed that the protein multilayers are composed of avidin monol ayers and enzyme monolayers which in turn are built in a layer-by-layer str ucture. The GOx and LOx enzymes were found to be catalytically active in th e multilayer films, by means of a cyclic voltammetry. The response characte ristics of the GOx- and LOx-modified sensors are discussed. (C) 1998 Elsevi er Science S.A. All rights reserved.