An antibody ordered assembly functional BPE-ECL platform for aflatoxin B1 detection

Abstract

Abstract Due to the complex characteristics of food matrix, inaccurate results are likely to occur when using traditional methods to detect Aflatoxin B1 (AFB1). In this paper, a biosensor based on closed bipolar electrode (BPE) has been developed to detect highly toxic AFB1 in mycotoxins. The biosensor uses cathode of closed BPE as a functional sensing interface and anode as a signal collection interface. On the functional sensing interface, monoclonal antibody connecting AFB1 at the top of DNA tetrahedron structure. In the presence of horseradish peroxidase (HRP), hydrogen peroxide (H2O2) catalyzes the oxidation of 4-chloro-1-naphthol (4-CN) to produce insoluble precipitations (4-CD). AFB1 competes with HRP-AFB1 to bind monoclonal antibody, resulting in a decrease in the content of HRP involved in catalytic oxidation reactions and a synchronous reduction in precipitations produced. Due to the electron transfer is influence by precipitation capacity, the decrease in precipitations lead to an increase in the BPE anode luminescence signal. On the signal collection interface, AFB1 detection is achieved by measuring the ECL strength of the [Ru(bpy)3]2+/TPA system. Through the above methods, the target does not need to participate in the ECL reaction of the anode, avoiding the direct contact between the photoactive molecules and the complex food matrix. The analysis shows that the relative deviation from ELISA is between − 4.5 ~ 9.8%, indicating that there is no significant difference between the biosensor and ELISA. The BPE-ECL sensor exhibits high sensitivity and specificity in detecting AFB1, with a linear range of 0. 01–40 ng mL− 1 and a detection limit of 3 pg mL− 1. It can be further applied to the detection of different kinds of toxins and has broad application prospects.