Fluorescence/colorimetric sensor based on aptamers-molecular imprinted polymers synergistic recognition for ultrasensitive and interference-free detection of aflatoxin B1.

This work aimed to develop a fluorescence/colorimetric sensor for the ultrasensitive detection of AFB1 based on the aptamers and molecular imprinted polymers (MIPs). The polydopamine on FeO (FeO@MIP) was used to achieve efficient separation of AFB1. The aptamer-modified carbon dots and metal-organic frameworks (Apt-CDs@MOF) were used to form sandwich particles (FeO@MIP-AFB1-Apt-CDs@MOF). The sandwich particles were separated and removed using magnets, and the remaining Apt-CDs@MOF in suspension was used for both fluorescence and colorimetric detection. The sensor reached the linear range of 0.05-150 ng mL (fluorescence channel) and 0.1-100 ng mL (colorimetric channel). The detection limit can be as low as 37.0 pg mL (fluorescence channel) and 13.0 pg mL (colorimetric channel). Through the clever use of sandwich structure, the sensor represents a novel method for interference-free detection of AFB1. The proposed sensor effectiveness was further validated by quantifying AFB1 in untreated edible oil, which shows great potential for application.