From engineered photoactive materials to detection signal amplification strategies in photoelectrochemical biosensing of pathogens: New horizons and perspectives

The ubiquitous pathogens pose a direct threat to human health at present. Undeniably, traditional detection methods are still irreplaceable in many respects. However, the appearance of emerging detection technologies has injected new vitality and yielded unexpected achievements in the detection field. Photoelectrochemical (PEC) biosensors have shown great application prospects in pathogens detection with the unique advantages of miniaturization, high sensitivity, simple operation, and fast response. Meanwhile, the introduction of nanomaterials and biorecognition elements endows superior performance of the PEC biosensors. In this review, the designs of engineering photoactive materials are summarized, focusing on the popular types of heterojunctions with different charge-transfer mechanisms, defect engineering, surface sensitization, morphological and structural regulation. Then, we emphasize the importance of signal amplification strategies applied in PEC biosensors to improve detection sensitivity. On this basis, we comprehensively review the applications and biosensing mechanisms of PEC biosensors for detecting different pathogens in the past decade. Finally, the current challenges and prospects of PEC biosensors in the fields are proposed, especially for on-site applications.