An excellent enzyme biosensor based on Sb-doped SnO2 nanowires

Sb-doped SnO2 nanowires were synthesized via thermal evaporation. Scanning electron microscopic, transmission electron microscopic, X-ray diffraction, current voltage, and electrochemical impedance spectroscopy experiments have been used to characterize the structural and electrical behaviors of the nanowires. A mediator-free horseradish peroxidase-based H2O2 biosensor was constructed through the Sb-doped SnO2 nanowires used as the immobilization matrix for the enzymes. In comparison with the undoped SnO2 nanowires, Sb-doped SnO2 nanowires exhibited excellent electron transfer properties for the enzymes and higher electroactivity toward H2O2. The biosensors displayed good performance along with high sensitivity, wide linear range, and long-term stability. Those can be attributed to the enhanced carrier density arising from Sb doping and biocompatible microenvironment provided by the Sb-doped SnO2 nanowires. This study demonstrated that Sb-doped SnO2 nanowires were promising platform for the construction of mediator-free biosensors and provided new further fundamental insights into the study of nanoscience and nanodevices. (C) 2010 Elsevier B.V. All rights reserved.