Fabrication of a novel glucose biosensor based on Pt nanoparticles-decorated iron oxide-multiwall carbon nanotubes magnetic composite

A sensitive and selective amperometric glucose biosensor was obtained by using the electrodeposition of Pt nanoparticles on iron oxide-multiwall carbon nanotubes/chitosan (FeyOx-MWCNTs/CS) magnetic composite modified glassy carbon electrode (GCE) followed by the adsorption of glucose oxidase (GOx) at the surface of the electrode. FeyOx-MWCNTs magnetic composite was characterized by transmission electron microscopy (TEM). The modified process and the electrochemical characteristics of the resulting biosensor were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry. The proposed biosensor exhibit excellent electrocatalytic activity and good response performance to glucose. The influence of various experimental conditions was examined for the determination of the optimum analytical performance. Under the optimal conditions, a linear dependence of the catalytic current upon glucose concentration was obtained in the range of 6.0 x 10(-6) to 6.2 x 10(-3) M with a detection limit of 2.0 x 10(-6) M, and a response time of less than 8s. The apparent Michaelis-Menten constant (K-M(app)) was evaluated to be 9.0 mM. Furthermore, the sensitivity for the determination of glucose at the GOx/Pt/FeyOx-MWCNTs/CS magnetic composite modified GCE is better than at common GOx/Pt/MWCNTs/CS and GOx/Pt-FeyOx/CS composite modified electrodes. The proposed biosensor has good anti-interferent ability and long-term storage stability after coating with Nation, and it can be used for the determination of glucose in synthetic serum. (C) 2010 Elsevier B.V. All rights reserved.