An electrochemical sensor based on curcumin-encapsulated zeolitic imidazolate framework-8 for the sensitive determination of aflatoxin B1 in grain products

A sensitive voltammetric electrochemical immunosensor was developed for the detection of aflatoxin B1 (AFB1) using anti-mouse immunoglobulin IgG labeled with curcumin@zeolitic imidazolate framework-8/polydopamine (CCM@ZIF-8/PDA/IgG) as a signal probe. ZIF-8 exhibited strong adsorption properties due to its large specific surface area, which greatly improved the encapsulation of CCM in the signal probe. CCM with remarkably electrochemical properties, PDA with good conductivity and ZIF-8 cooperated to enhance the analytical performance. Under optimum conditions, the peak current of the modified electrode decreased with the increment of AFB1 within a linear range of 0.5 pg mL−1 to 10 ng mL−1 and detection limit of was 0.11 pg mL−1. The immunosensor also presented outstanding selectivity and long − term stability. In addition, it was well employed to detect AFB1 in spiked rice and wheat samples with acceptable recoveries (86.65–105.20%), and was well verified by HPLC.