Effects of Enzyme Concentration and Film Thickness on the Analytical Performance of a Polypyrrole/Glucose Oxidase Biosensor

Abstract

We describe the effect of preparation conditions during electropolymerization such as enzyme concentration in the deposition solution and film thickness on the analytical performance of the resulting polypyrrole / glucose oxidase (PPy/GOD) film. The responses of the resulting PPy/GOD biosensor to glucose and ascorbate were characterized and optimized. It was found that the enzyme concentration 1017 Copyright 8 1995 by Marcel Dekker, Inc. Downloaded by [Monash University Library] at 12:01 04 December 2014 1018 SHIN AND KIM and the film thickness have the equivalent effects on the response of the resulting biosensor and that several optimal sets of the two parameters exist. The investigations regarding the response characteristic and the suppression of interference clearly indicate that the performance of biosensor could be significantly improved by making the film thick at low enzyme concentration.

Enzyme−Electropolymer-Based Amperometric Biosensors: An Innovative Platform for Time−Temperature Integrators

“…However, at larger GOD concentrations, the current response remained unchanged and slightly decreased at 10 g L -1 . This behavior is in agreement with previous reports ( , ). At low GOD concentrations, diffusion of glucose, O 2 and H 2 O 2 throughout the immobilization matrix is rapid and enzyme kinetics limits the overall rate of reaction and is proportional to enzyme concentration, as described by eq 2.…”

Improved platinization conditions produce a 60-fold increase in sensitivity of amperometric biosensors using glucose oxidase immobilized in poly-o-phenylenediamine

“…This decrease in response is attributed to a transition between kinetically controlled and diffusion controlled regimes that has been reported for polypyrrole-based sensors [11]. As the concentration of enzyme increases, substrate is consumed in an outer layer of the immobilization matrix and larger amounts of H 2 O 2 , the product of the enzy- I / µA Fig.…”

“…Finally, redox mediators have been polymerized and hence have been shown to work as both enzyme hosts and charge mediators [10]. The effects of enzyme concentration [11,12], monomer type [7] and concentration, ion nature and concentration [13] and buffer [14] on the electrochemical response to the analyte of interest [15] have been determined. In spite of the extensive research mentioned above, enzyme biosensors based on electrochemically generated polymers have two main deficiencies: their sensitivity remains relatively low and their long-term stability has not been demonstrated.…”

A Novel Nonenzymatic Hydrogen Peroxide Sensor Based on a Polypyrrole Nanowire-Copper Nanocomposite Modified Gold Electrode

“…For these reasons it has attracted considerable attention and many articles have reported its applications in biosensors [20, 21]. PPy film could be further improved by embedding metal particles into the polymer matrix to form a metal–polymer composite [22, 23].…”