Modification of Ferrocene-Containing Redox Gel Sensor Performance by Copolymerization of Charged Monomers

Enzyme electrodes were fabricated by entrapping glucose oxidase (GOx) in charged ferrocene-containing redox gels formed by the copolymerization of vinylferrocene−hydroxypropyl-β-cyclodextrin inclusion complex, acrylamide, and N, N ‘-methylenebis(acrylamide), together with a positively or negatively charged monomer at pH 7, in the presence of GOx in aqueous solution. The one-step polymerization procedure was initiated by a ternary catalyst system consisting of flavin mononucleotide, H 2 O 2, and N, N, N ‘, N ‘-tetramethylethylenediamine. The effects of varying the concentration and structure of the charged monomers on the electrochemical properties of the charged redox gels with and without GOx were investigated, and the pH−activity profiles of entrapped GOx were examined. The storage and operational stabilities of the sensors were established, and the influence of the interferents ascorbic acid, acetaminophen, and uric acid, which are present in body fluids, on the amperometric signals of the sensors was determined.