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/Fe 3 O 4 –NH 2 /GN) nanocomposite has been developed. The Fe 3 O 4 –NH 2 nanoparticles were self-assembled on GN, and then Fe 3 O 4 –NH 2 /GN nanocomposite was coated on the glassy carbon electrode (GCE) surface. Afterward, Au NPs were electrodeposited on Fe 3 O 4 –NH 2 /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 × 1 0 − 1 3 M to 1 × 1 0 − 7 M, the detection limit is 1 . 1 6 × 1 0 − 1 4 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.