Molecularly imprinted electrochemical sensor based on biomass carbon decorated with MOF-derived Cr2O3 and silver nanoparticles for selective and sensitive detection of nitrofurazone.

• Biomass carbon, Ag NPs and Cr-MIL-101 derived Cr 2 O 3 were used to enhance conductivity. • MOF-derived metal oxides retain the MOF morphology. • Bifunctional monomers were used to enhance the specificity of MIP for NFZ. • Wide linear range of 5 × 10−9–1 × 10−5 M were obtained, along with low detection limit of 3 × 10−9 M. In the work, a novel molecularly imprinted electrochemical sensor was proposed for sensitive and rapid detection of nitrofurazone (NFZ). The sensor was modified with Cr 2 O 3 derived from metal-organic framework (MOF), silver nanoparticles (Ag NPs) and biomass carbon (BC) from walnut shells. Among them, Ag NPs are grown on the surface of Cr-MIL-101 to obtain Cr-MIL-101/Ag, and then calcined with BC to obtain a composite material BC/Cr 2 O 3 /Ag. This material improves the effective surface area and electron transfer capability of the electrode to increase current response. Adding molecularly imprinted polymer (MIP) to the surface of composite materials can improve the specific recognition ability of modified electrodes for NFZ. MIP was prepared by precipitation polymerization using acrylamide (AM) and α-methacrylic acid (MAA) as bifunctional monomers and NFZ as the template. Under the most suitable experimental environment, the differential pulse voltammetric (DPV) current response of modified electrode (BC/Cr 2 O 3 /Ag/MIP/GCE) to NFZ showed a good linear relationship between 5 × 10−9 −1 × 10−5 M, and the detection limit was 3 × 10−9 M. This sensor has high sensitivity, selectivity, reproducibility and stability. Moreover, BC/Cr 2 O 3 /Ag/MIP/GCE was applied for the detection of NFZ in real samples. BC/Cr 2 O 3 /Ag/MIP/GCE provides a reliable approach for determination of NFZ in biological fluids. [ABSTRACT FROM AUTHOR]