Effective Strategies on Fabricating Photoelectrode Materials for Enhancing Photoelectrochemical Sensing

Photoelectrochemical (PEC) sensors, as a rapidly developing and highly promising method for detection and analysis, show the advantages of low background noise and high sensitivity by virtue of the separate "photoexcitation-electrical detection signal" mode. It is attracting increasing attention in fields such as environmental monitoring and pharmaceutical analysis. The working mechanism of PEC sensor is recording the change of electrical signals caused by the recognition reaction between the measured substance and the photoelectrode. The photoresponsive materials on electrodes play a central role in the conversion of light into electrical signal, and it can directly affect the sensitivity of the sensor element. Designing and constructing highly active photoelectrode is key to improve the performance of PEC sensor, but it also presents significant challenges. Based on the above, this paper reviews a variety of electrical signal enhancement strategies through fabricating effective photoelectrode materials, such as constructing heterojunctions, modifying cocatalysts, doping elements, and sensitization of quantum dots, etc., aiming to provide valuable solutions to achieving excellent sensing performance of PEC analysis platforms. Finally, some future opportunities and challenges of PEC sensors are also discussed.