Glucose photoelectrochemical enzyme sensor based on competitive reaction of ascorbic acid.

A new method based on the competitive reaction of ascorbic acid (AA) was used to improving the performance of photoelectrochemical glucose enzyme sensor. In this method, amplifying the photoelectric signal of H2O2 by the competitive reaction of AA is the key step. The detection can be well operated at 0 V under optimal AA concentration of 10 mM. In the method, AA was regarded as not only the electron donor to capture the hole in the conduction band of ZnO, but also the remover of H2O2 produced by the oxidation of glucose. Both these factors led to the formation of a pair of competitive reactions that enhanced the response towards glucose detection. Compared to the detection without AA, the stability of the response current, detection ranges of 1-19 mM, detection limit of 80 μM and sensitivity of 2.88 μA mM-1·cm-2 were optimized prominently.