A conductive ormosil encapsulated with ferrocene conjugate and multiwall carbon nanotubes for biosensing application

Highly non-toxic and conductive ormosil composite film was prepared using (3-aminopropyl)triethoxysilane and 2-(3,4-epoxvcvclohexyl)-ethyltrimethoxysilane by doping with ferrocenernonocarboxylic acid-bovine serum albumin (FMC-BSA) conjugate and multiwall carbon nanotubes (MWNTs). With glucose oxidase (GOD) as a model enzyme this film could be used to design an amperometric biosensor for glucose determination. The entrapped FMC-BSA conjugate performed excellent redox electrochemistry and the immobilized GOD was highly stable. Under optimal conditions this biosensor was able to detect glucose with a detection limit of 20 mu m (S/N = 3) in the linear range of 0.05-20.0 mM in flow system, which was wider than the batch amperometric mode, with an analysis time of 25 s for each sample. The value of k(M)(IPP) as 6.6 mM. The proximity of these three components FMC-BSA, MWNTs and GOD enhanced the electron transfer between the film and electrode. This film could be used efficiently for the entrapment of other redox bioactive compounds and biosensing/bioelectrochemical applications. (c) 2005 Elsevier Ltd. All rights reserved.