Molecularly Imprinted Electrochemistry Sensor Based on AuNPs/RGO Modification for Highly Sensitive and Selective Detection of Nitrofurazone

Nitrofurazone (NF) is a kind of synthetic antibiotic with teratogenic and carcinogenic properties, which is often residual in animal food, so it is of great significance to detect it with high selectivity and rapid. In this study, a molecularly imprinted electrochemical sensor was constructed by electropolymerization for the high-specificity, high sensitivity,and rapid detection of NF in milk. By sequentially modifying reduced graphene oxide (RGO) and gold nanoparticles (AuNPs) on the glassy carbon electrode, the effective surface area and electron transfer ability of the electrode are improved, the double amplification of the electrical signal is realized, and the sensitivity and stability of the sensor are improved. A molecularly imprinted polymer (MIP) is polymerized on the surface of the modified electrode by using NF as a target molecule and o -phenylenediamine ( o –PD) as a functional monomer to improve the specific detection ability of the sensor for NF. The experimental conditions (the number of turns of depositing RGO, the thickness of the MIP, the elution time, and the adsorption time) were optimized to attain the best detection performance of the sensor. Differential pulse voltammetry (DPV) was used to detect NF by redox probe ([Fe(CN) 6 ] 3−/4− ). The constructed sensor exhibited an admirable linear relationship between 5 and 1000 nmol L −1 ( R 2 = 0.9968) and the detection limit was 0.18 nmol L −1 (S/N = 3). Compared to the non-imprinted sensor, the imprinting factor was found to be 3.09. In addition, the sensor also showed excellent repeatability (RSD = 1.17%) and stability, and also showed a good recovery rate in actual sample detection (99.06–101.46%), which is expected to be applied to the detection of other harmful substances in food.