Colorimetric sensor comprising metal-organic frameworks and molecularly imprinted polymers for aflatoxin B1 detection...

A novel colorimetric sensor was developed by integrating cerium metal-organic frameworks with molecularly imprinted polymers (Ce-MOF@MIP) for the highly selective and sensitive detection of Aflatoxin B1. The resulting composite leverages the peroxidase-like activity of cerium metal-organic frameworks to catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine in the presence of hydrogen peroxide, while imprinted cavities confer specificity toward Aflatoxin B1. Detection is facilitated by monitoring the inhibition of the composite's catalytic activity, manifesting as colorimetric changes that can be quantified using ImageJ. The sensor exhibits two linear detection ranges (0.5-5 ng mL^-1 and 5-50 ng mL^-1) and achieves a detection limit of 0.25 ng mL^-1. When applied to agricultural samples (peanuts, chicken feed, and corn), recoveries ranged from 95.1 % to 109.4 %, surpassing high-performance liquid chromatography according to a paired t-test. Taken together, these findings highlight the sensor's high sensitivity, selectivity, and robustness, underscoring its promise in food safety applications and broader mycotoxin surveillance.