Bio-sensing property of gold coated ZnO nanorods
- Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India
- Received 2 August 2013
- Accepted 24 November 2013
- Available online 1 December 2013
Improvement in the performance of glucose bio-sensor based on ZnO nanorod (ZnO NR) upon gold coating.
Gold coated ZnO NR based bio-sensor has wider range of linear detection.
Electron transfer rate for gold coated ZnO NR is better than bare ZnO NR.
Maximum biosensor activity occurs at pH=7 and thus ideal for bio-sensing application.
In this paper we bring forward our report on improved performance of gold coated ZnO nanorod (ZnO NR) over pristine ZnO NR based glucose bio-sensors. The ZnO NR was electrochemically deposited on indium tin oxide (ITO) substrate. Cyclic voltammetric study showed that there was an increase in the oxidation current when the gold layer was coated on the ZnO NR. Further, amperometric comparison showed that the gold coated ZnO NR has a wider linear detection range than pristine ZnO NR based sensor. We have studied the optimum performance of the sensor as a function of temperature and pH. We have also compared the charge transfer properties using electrochemical impedance spectroscopy (EIS). The EIS data shows that the electron transfer rate for gold coated ZnO NR is better than pristine ZnO NR. Therefore, better electron transfer rate results in better biosensing property of gold coated ZnO NR.