Photoelectrochemical performance and biosensor application for glutathione (GSH) of W-doped BiVO4 thin films

Tungsten-doped BiVO 4 (W:BiVO 4 ) thin films were deposited on the FTO glass through a spin-coating method and their photoelectrochemical (PEC) properties were investigated. Although W-doping does not significantly affect the morphology, structure and light harvesting a suitable W-doping treatment can enhance the PEC activity of BiVO 4 thin films, leading to a 100% enhancement of the photocurrent. It is found that the doping of 10 at.% W leads to an increased photocurrent from 0.75 mA cm −2 (for undoped) to 1.5 mA cm −2 . Moreover, through an electrochemical impedance analysis, the enhancement of PEC performance was mainly due to the enhanced n -type conductivity of BiVO 4 and charge separation at the solid/liquid interface. A scheme model was proposed to clarify the reason for performance enhancement. Moreover, a PEC biosensor was fabricated for detecting the glutathione, leading to an excellent detect limit of 96 nM.