A simple strategy for one-step construction of bienzyme biosensor by in-situ formation of biocomposite film through electrodeposition

One-step construction of horseradish peroxidase (HRP) and glucose oxidase (GOD) bienzyme biosensor was established based on a simple and controllable electrodeposition approach by in-situ formation of biocomposite film on electrode. With hydrogen peroxide (H2O2) instantly generated by GOD-catalyzed oxidation of glucose, quantitative measurement of glucose could be achieved. In the proposed electrodeposition strategy, Concanavalin A (Con A) was applied as bifunctional cross-linker for in-situ incorporating of HRP-GOD in biocompatible chitosan (CS) matrix due to its biospecific affinity interaction with CS and glycoproteins. Scanning electron microscopy showed that the HRP-GOD/Con A/CS biocomposite film possessed highly porous surface. The developed bienzyme biosensor exhibited a fast amperometric response for the determination of glucose. The linear response of the developed biosensor for the determination of glucose ranged from 1.0 x 10(-6) to 2.2 x 10(-4) M with a detection limit of 6.7 x 10(-7) M. The biosensor can be used to determine glucose in serum directly. The biosensor presented high stability owing to the design of the introduction of Con A and instant generation of H2O2 with bienzyme system. The one-step construction of biosensor based on non-manual technique in biocompatible environment was direct and facile. (C) 2009 Elsevier B.V. All rights reserved.