An amperometric glucose biosensor based on a GOx-entrapped TiO2-SWCNT composite

Single-walled carbon nanotubes (SWCNT) were deposited onto indium tin oxide (ITO)-coated glass using an arc-discharge method. Titanium oxide (TiO2) was coated onto the SWCNTs using a metal-organic chemical vapor deposition (MOCVD) technique. The surface morphology and crystal structure of a TiO2-SWCNT nanowire structured composite was investigated using FESEM, XRD and Raman spectra. The TiO2-SWCNT composite film was used to immobilize glucose oxidase (GOx). The immobilization of GOx onto TiO2-SWCNT composite film was characterized by FTIR spectroscopy. The glucose-sensing properties of a GOx/TiO2-SWCNT/ITO electrode was studied at -0.25 V, and it showed a linear range of detection from 10 mu M to 1.40 mM in a response time of 9s with a low detection limit of 10 mu m and a sensitivity of 5.32 mu A mM(-1) cm(-2). The Michaelis-Menten constant was 0.83 mM. The effects of interfering species like uric acid, ascorbic acid and sucrose were also studied. (C) 2012 Elsevier By. All rights reserved.