A sensitive photoelectrochemical biosensor for pesticide detection based on BiVO₄

ABSTRACT

A sensitive photoelectrochemical biosensor was constructed for the detection of chlorpyrifos. The sensor was prepared on indium tin oxide (ITO) electrode using photoelectric material bismuth vanadate (BiVO₄) and acetylcholinesterase (AChE). It is found that the photocurrent of ITO/BiVO₄ electrode was largely dependent on its treatment temperature. The highest anodic photocurrent response of the ITO/BiVO₄ photoelectrode was obtained after the treatment at 300°C. The thiocholine, produced in the catalytic reaction at ITO/BiVO₄/AChE electrode surface, can greatly enhanced the anodic photocurrent. In addition, the adsorption of chlorpyrifos on the surface of the AChE caused a decrease in the intensity of the photocurrent. Under the optimisation of experimental conditions, the decrease of the photocurrent showed a good linear range from 1 pM to 10 nM under irradiation of visible light. The detection limit is calculated as 0.25 pM with a 10% inhibition rate. The ITO/BiVO₄/AChE photoelectrode exhibited high sensitivity, acceptable stability and good reproducibility. The biosensor can be provided to the potential applications for detection of pesticide residues in food.

KEYWORDS:

• Photoelectrochemical
• biosensor
• BiVO₄
• chlorpyrifos

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China (No. 21475092).