A fuel-free photocatalytic self-powered sensor for ultrasensitive aflatoxin B1 detection in Moldy corns

Aflatoxin B1 (AFB1), as the most toxic Aspergillus flavus, its ultrasensitive detection is urgent. Self-powered electrochemical sensor (SPES) has become a hot spot of research for its fast responses, simple operation and good stability. Herein, a dual-electrodes photocatalytic fuel cell-assisted self-powered electrochemical sensor (DPFC-SPES) was proposed for AFB1 detection by integrating fuel-free strategy with magnetic nanobeads (MBs)-assisted signal amplification strategy. The CdIn₂S₄/SnO₂ heterojunction was constructed and enhanced photocurrent about 73-fold compared with SnO₂. By introducing TaDp-COF-modified photocathode, DPFC-SPES with dual-electrodes boosted output potentials to 733.6 mV. The fuel-free strategy was proposed by utilizing cyclic reaction of photocathode and photoanode, greatly reducing battery internal resistance and saving energy. Moreover, MBs-assisted strategy was used to one-to-many signal amplification, realizing AFB1 detection with a detection limit down to 0.058 pg/mL. In addition, DPFC-SPES successfully achieved AFB1 detection in moldy corns, providing a further potent indication for food safety supervision and environmental monitoring areas.