Highly sensitive detection of aflatoxin B1 by in situ growth of electroactive polymers via ring-opening metathesis polymerization

In this study, an electrochemical sensor was fabricated for detecting aflatoxin B 1 (AFB 1 ) based on in situ-initiated ring-opening metathesis polymerization. The thiol-modified aptamer was first immobilized on the Au electrode through Au-S bonding to capture AFB 1 . Then, the acrylic acid (AA)-functionalized antibody specifically recognized AFB 1 and immobilized on the surface of the electrode. Finally, a large number of cyclopentenyl ferrocene (CFc) monomers were grafted onto the electrode surface under the action of the catalyst AquaMet, forming an electroactive long-chain polymer that results in a significant signal enhancement. Under optimal conditions, the detection limit of the method was 0.34 fg/mL with a detection range of 2 fg/mL-2 ng/mL. The proposed sensor is highly selective due to the high specificity of the aptamer and antibody to the target. In addition, the sensor has been successfully applied to detect AFB 1 in real samples with recoveries ranging from 92.91% to 107.20%. • ROMP was first used for the high sensitivity detection of AFB 1 . • A detection limit of 0.34 fg/mL was achieved based on the aptamer-antibody sandwich mode. • The proposed sensor is suitable for AFB 1 detection in complex actual samples. • The proposed sensor showed high sensitivity, selectivity, low cost, and good biocompatibility.