In Situ Heterojunction-based PEC Sensor Coupled with LSPR for Sensitive Detection of Aflatoxin B1

To enhance the performance of photoelectrochemical (PEC) sensors, heterojunction construction is a workable technique. However, the interface defects inside the structure are often ignored. In this work, an innovative photoelectrochemical (PEC) sensor based on a "turn-off" PEC model was constructed using the synergistic effects of in situ growing heterojunction and local surface plasmon resonance (LSPR) to detect Aflatoxin B1 (AFB1) instantly. In situ heterojunctions were constructed based on bismuth-based perovskite, and the internal electric field spontaneously established during the growth process can effectively compensate for the interfacial defects and promote the separation and transfer of e-/h+ pairs. Moreover, the gold nanoparticles (Au NPs) LSPR effect can improve PEC performance by enhancing the light trapping ability of the material. The PEC sensor's detecting area for AFB1 analysis is 10.0 fg/ml-100 ng ml-1, and the detection limit is 4.34 fg ml-1. Good stability, reproducibility, and selectivity underscore the sensor's suitability for meeting the requirements of food quality monitoring.