A dual-photoelectrode self-powered photoelectrochemical aptasensor based on metallophthalocyanine-sensitized photoanode amplification coupled with core-shell SiO2@Tb-MOF quenching.

Aflatoxin B1 (AFB1) poses severe threats to human health even at trace levels, necessitating the development of rapid and sensitive detection methods. This work presents an innovative self-powered photoelectrochemical aptasensor for ultrasensitive AFB1 monitoring. Specifically, zinc phthalocyanine-sensitized MgIn2S4 as a high-performance photoanode, where the sensitization narrows bandgap and extends light absorption, generating enhanced photocurrent for biological detection. Furthermore, Au@CuGaO2 as a stable photocathode that provides abundant biomolecule binding sites while circumventing the false-positive issues inherent in conventional anodic sensing platforms. Notably, SiO2@Tb-MOF as a dual-function quencher that simultaneously competes for visible light excitation and creates steric hindrance to block electron donor access, achieving significant signal amplification. The synergistic effects of these components yield exceptional analytical performance, including an ultra-wide linear range (0.01 pg/mL to 100 ng/mL) and a low detection limit (0.0032 pg/mL). The satisfactory anti-interference, reproducibility and stability provide a solid foundation for the application of this sensing platform.