An amperometric glucose biosensor based on a screen-printed electrode and Os-complex mediator for flow injection analysis

An amperometric Os-complex mediated glucose biosensor based on a three electrodes planar configuration was constructed using screen printing technique for flow injection analysis. The electrochemical characteristic of the amperometric biosensor was evaluated by the cyclic voltammetry in the absence and presence of Os-complex mediator. The Os-complex mediated biosensor was found to have a C–V curve close to an ideal. The applied potential of the biosensor had been explored and −0.1 V vs. Ag|AgCl reference electrode was selected for avoiding excessive interference from other electroactive species. The biosensor also indicated good stability of more than 90% of its original activity for about 14 months stored at 4 °C. The biosensor on the detection of glucose showed a linear response range of 0.5–30 mM and the correlation coefficient up to 0.99 together with a FIA system. The coefficient of variation was 3.3% for injections with a single biosensor (n = 12). The results show that the biosensor has fast response, good sensitivity and reproducibility for flow injection analysis.