A Sensitive Electrochemical Aptamer Sensor for Clenbuterol Detection Based on Au NPs/Fe3O4-NH2/GN Nanocomposite

Chronic ingestion of food containing clenbuterol (CLB) in the human body can cause acute poisoning. Thus, it is essential to develop a sensitive CLB detection way. Here, a novel electrochemical aptamer sensor based on aptamer/gold nanoparticles/amino magnetic ferric oxide/graphene nanosheets (aptamer/Au NPs/Fe3O4-NH2/GN) nanocomposite has been developed. The Fe3O4-NH2 nanoparticles were self-assembled on GN, and then Fe3O4-NH2/GN nanocomposite was coated on the glassy carbon electrode (GCE) surface. Afterward, Au NPs were electrodeposited on Fe3O4-NH2/GN nanocomposite to fix the aptamer by the Au-S bonds. When CLB was added to the solution, the aptamer will specifically recognize CLB, causing current changes. Under the optimized conditions, the sensor shows better electrochemical performance (linear range is 1 x 10(-13) M to 1 x 10(-7) M, the detection limit is 1.16 x 10(-14) M (S/N = 3)). It has been successfully applied to the detection of CLB in actual samples. The results show that the aptamer sensor has good selectivity, stability and repeatability, which will provide a novel idea for more sensitive and quicker CLB detection.