Self-powered portable photoelectrochemical sensor based on dual-photoelectrode for microplastics detection

Plastic pollution has emerged as a significant global concern due to its potential threat to human health. The advancement of self-powered photoelectrochemical (PEC) sensors based on dual-photoelectrode presents ongoing challenges. The photoanode PEC analysis method is normally employed due to its remarkable photocurrent and low detection limit; however, it exhibits limited anti-interference capability in real sample detection. Conversely, the photocathode analysis method demonstrates excellent anti-interference detection capabilities, effectively mitigating the inherent disadvantages associated with the photoanode. Consequently, we have developed a self-powered PEC portable sensor that integrates both a photocathode and a photoanode, enabling accurate, sensitive, and convenient detection of polystyrene microplastics (PS MPs). Under optimal conditions, the sensor has a detection limit of 0.09 μg/mL, with a linear range from 0.5 to 1000 μg/mL. The method has good anti-interference ability to heavy metal ions and organics. In the presence of interfering substances, the accuracy can be maintained at over 97%. In addition, the sensor has demonstrated excellent performance in complex aquatic environments, providing an innovative design strategy for constructing PEC sensors aimed at detecting PS MPs.