Photocurrent switching effect on BiVO4 electrodes and its application in development of photoelectrochemical glucose sensor

In this work, we reported the photocurrent switching effect on BiVO4 semiconductor as well as its application for construction of a new cathodic photoelectrochemical (PEC) biosensor. Specifically, the photocurrent switching effect of BiVO4 upon fluorine doped tin oxide (FTO) glass substrate was greatly dependent on its treatment temperature and composition of solution in the cell. The photocurrent transition potential from anode to cathode is similar to 0.38 V (vs SCE) in the presence of O-2. H2O2 can act as electron acceptor to improve cathodic PEC current at electrode treated under 500 degrees C. A cathodic PEC biosensor of glucose was designed based on glucose oxidase (GOD). The GOD/BiVO4/FTO photoelectrode exhibited high sensitivity towards the enzyme reaction production of H2O2. This PEC biosensor shows a good response on the concentration of glucose and exhibits a dynamic range of 1 similar to 400 mu M with a detection limit of 0.73 mu M. Interference from oxygen fluctuation was negligible. The present work provides a promising approach to develop other oxidase-based PEC biosensors.