The synergistic of oxygen vacancies–driven and proportional Cd1–xZnxS mediated signal reversal photoelectrochemical sensor for CYFRA21–1 detection

Studies have shown that non–small cell lung cancer is a malignant disease with a large number of malignant tumors. As a result, it is widely recognized by researchers that achieving sensitive detection of the non–small cell lung cancer biomarker cytokeratin 19 fragment (CYFRA21–1) is essential. Combining the advantages of photoelectrochemical (PEC) sensors, a polarity reversal transition PEC sensor was successfully constructed to achieve sensitive detection of CYFRA21–1. An s–type heterojunction Bi2WO6–ε/BiO1–δI containing oxygen vacancies is used for the construction of this sensor and can be used to enhance the electron–hole mobility by an internal electric field. Incorporating Ag@PDA serves as a pivotal linkage, a novel and less applied linker. The addition of Ag@PDA provides more active sites for better linkage. The selected marker is proportional Cd1–xZnxS, which can obtain the best photoelectric response by optimizing the feeding ratio of Cd and Zn. The synergistic effect of oxygen vacancies–driven and proportional Cd1–xZnxS mediated signal reversal photoelectrochemical sensor can achieve sensitive detection of CYFRA21–1 with a detection range of 1 pg/mL ~ 100 ng/mL and a detection limit of 0.51 pg/mL. This research may open up a new promising PEC strategy for some other antigen proteins analysis.