A sensitive photoelectrochemical aptasensor based on Bi/Bi₂MoO₆-modified phosphorus-doped ultrathin g-C₃N₄ formed...

Tetracycline (TC) is a common antibiotic with broad antibacterial activity, yet its excessive abuse will leave antibiotic residues in animal-derived food, posing some threats to human health. Therefore, developing a simple and effective technology for TC trace analysis is immediately important for food safety. Herein, the sensitive PEC aptasensor within Z-scheme heterojunction, based on Bi/Bi₂MoO₆ and P-doped ultrathin porous g-C₃N₄ (PCN), was constructed by elemental doping strategy, hydrothermal method and surface plasmon resonance (SPR) effect. Benefiting from the Z-scheme electron transmission way, the Bi/Bi₂MoO₆@PCN heterojunction significantly improves both visible-light absorption and the mobility of photogenerated carriers. Thus, the fabricated PEC aptasensor based on Bi/Bi₂MoO₆@PCN heterojunction exhibited outstanding selectivity and stability for TC detection, which displayed a wider linear range of 0.05-350 nM and a lower detection limit of 0.036 nM. In addition, the proposed aptasensor showed the acceptable recoveries (98.41-104.76 %) for TC residue analysis in animal-derived food, including milk, honey and pork. Therefore, it demonstrates that the PEC sensing technology possesses the excellent feasibility and application potential in food analysis.