Photoelectrochemical Sensors for the Detection of Disease Biomarkers: Principles and Applications

The rapid and accurate detection of disease biomarkers is crucial for the early diagnosis, prognosis assessment, and therapeutic monitoring of major diseases, including cancer, cardiovascular diseases, inflammatory responses, and infectious diseases. Conventional analytical techniques such as enzyme-linked immunosorbent assay (ELISA), mass spectrometry, and nucleic acid amplification, while reliable, are often constrained by complicated procedures, high cost, and limited applicability in point-of-care settings. In response to the aforementioned challenges, photoelectrochemical (PEC) sensors have garnered significant attention in recent years due to their advantages of low background noise, high sensitivity, and simple instrumentation, emerging as a promising direction in biosensing. This review systematically elucidates the fundamental operating principles of PEC biosensors and summarizes the key functional materials involved in their construction (such as semiconductor optoelectronic materials, photosensitizers, and electron transport aids) and their interfacial regulation strategies. Furthermore, recent progress in the application of PEC sensors for the detection of disease-related biomarkers is critically examined, with representative examples targeting cancer-associated proteins, cardiovascular disease markers, inflammatory mediators, pathogen-derived nucleic acids, and antigens. The performance of different detection strategies is also compared in terms of sensitivity, selectivity, and practical feasibility. Finally, the challenges hindering the broader application of PEC biosensors are discussed. Future perspectives are outlined, highlighting material innovation, interfacial optimization, and device miniaturization as key directions to advance PEC biosensors toward clinical translation and portable diagnostic applications.