Polymer-Complex Mediated Enzyme Electrodes for Amperometric Determination of Glucose

Abstract

Abstract The immobilized enzyme chemically modified solid-state electrodes based on bilayer-film coating for amperometric determination of glucose have been fabricated and their sensor characteristics have been examined. The electrode substrate was coated with two kinds of polymeric films in a bilayer state, that is, System I: first with the cobalt tetrakis(o-aminophenyl)porphyrin polymer (poly-CoTAPP) film and then with an enzyme film consisting of bovine serum albumin and glucose oxidase (GOx), and System II: first with the Ru(NH3)3+ 6-containing montmorillonite clay film and then with the GOx enzyme film. The glucose concentration could be monitored by measuring the currents corresponding to the O2 reduction and the H2O2 reduction which are electrocatalyzed by the poly-CoTAPP film (System I) and the clay film (System II), respectively. The reproducible relationship between glucose concentration and sensor output was obtained for both systems with a dynamic range of ∼ 1-100 mM (for System I as an electrochemical detector for a flow injection analysis) and ∼0.4-4 mM (for System II). In addition, the sensors showed long-term stability (more than 1 and 2 months in System I and System II, respectively) and relatively rapid response (response times of System I and System II are − 5-10 and 40-60 s, respectively).