A polyazophenylglycine attapulgite electrochemical immunosensor with a high electronegative surface for sensing aflatoxin B1 with high sensitivity and precision†

Aflatoxin B1 (AFB1) is one of the most harmful mycotoxins to human and environmental health. In this paper, a novel electrochemical AFB1 immunosensor using attapulgite composite N-phenylglycine as a conductive material is developed. The strong π–π and electrostatic interactions between the AFB1 antibody and the nanomaterial are investigated. The developed electrochemical AFB1 immunosensor exhibits high sensitivity, with a detection limit of 0.011 ng mL⁻¹ and a quantitation limit of 0.035 ng mL⁻¹ (S/N = 3). The recoveries for three different concentrations of AFB1 range from 97.5% to 104.6%, with a relative standard deviation of stability less than 2.0%. ATP-PNPG possesses more oxygen defects and adsorbed oxygen than ATP-NPG. These properties enhance its electronegativity and make it more conducive to detecting low concentrations of AFB1 through electrochemical sensing technology. Finally, the electrochemical AFB1 immunosensor demonstrates good selectivity, stability, and reusability for detecting AFB1 in corn samples, exhibiting a high recovery rate.