A novel dual-template molecularly imprinted polymer ratiometric fluorescence sensor based on three-emission carbon quantum dots for accurate naked-eye detection of aflatoxin B1 and zearalenone in vegetable oil

A molecularly imprinted polymer (MIP) fluorescence ratiometric sensor based on three-emission carbon quantum dots (CDs) was successfully developed and used for the visual detection of aflatoxin B1 (AFB1) and zearalenone (ZEN). To this end, the optimal ratio of MIP and the reaction site were first calculated by density functional theory. Fluorescence sensors based on B/GCDs/MIPs and B/RCDs/MIPs were then prepared by the sol-gel method. Finally, the visual detection of AFB1 and ZEN from yellow-green to yellow, red, violet, and finally blue was realized after mixing. Compared to the double-emission ratiometric sensor, the mixed three-emission ratiometric sensor revealed richer fluorescence color evolution and higher sensitivity. Under the optimal conditions, the sensing platform induced fluorescence signals of AFB1 and ZEN within 30 s with dynamic linear ranges of 0.01–100 ng/mL and 0.03–100 ng/mL, as well as detection limits of 3.2 pg/mL and 18 pg/mL, respectively. In sum, insights into the visual recognition and construction of rapid detection platforms of AFB1 and ZEN were provided, promising for future food analysis.