A self-reporting electrochemical sensor for carbendazim in food based on magnetic molecularly imprinted MOFs

A novel electrochemical sensor for highly sensitive and selective detection of carbendazim (CBD) in food was proposed in this study. Initially, a three-dimensional carbon composite material (CCM) was formed by simultaneously modifying reduced graphene oxide and reduced graphene nanoribbons on the glassy carbon electrode (GCE) to enhance sensitivity and serve as a stable sensing platform. Then copper nanoparticles were electrodeposited on CCM/GCE, and cyclic voltammetry scanning was performed in potassium ferrocyanide solution to deposit copper-based Prussian blue analogue on CCM/GCE, further improving the sensitivity of the sensor while giving the ability to self-report. Magnetic molecularly imprinted metal-organic framework materials were then dropped onto the electrode to enhance its detection specificity and adsorption capacity for CBD. The sensor has a wide linear range (0.25 nmol/L ∼ 1000 nmol/L) and a low detection limit (0.08 nmol/L), and the recovery rate of CBD in actual corn flour samples is 99.74 % ∼ 102.58 %.