A novel multimode biosensor for sensitive detection of AFB1 in food based on Mxenes nano enzymes

In this work, Ti3C2 nano-enzymes (Ti3C2 NEs) materials with simulated peroxidase activity and fluorescence quenching properties were prepared. Then Ti3C2 NEs was functionalized using 6-carboxyfluorescein (FAM) labeled Aflatoxin B1 (AFB1) aptamers to construct a novel multimode nano enzyme biosensor for the detection of AFB1 in peanuts. Based on the fluorescence quenching characteristics and the superior simulated peroxidase activity of Ti3C2 NES and the specific binding of the aptamer to AFB1, the sensitive and rapid fluorescence/ colorimetric/smart phone detection of AFB1 have been achieved, with detection limits of 0.09 ng mL-1, 0.61 ng mL-1 and 0.96 ng mL-1, respectively. The analytical method provided can not only detect AFB1 in multiple modes, but also has a wider detection range, lower limit of detection (LOD) and better recovery rate, and can achieve on-site accurate detection of AFB1 content in peanuts, which has great application potential in the field of food quality testing.