Electrochemical determination of nitrofuran residues at gold nanoparticles/graphene modified thin film gold electrode

Highly sensitive detection of nitrofurazone (NF) and semicarbazide (SC) with an electrochemical sensor based on gold nanoparticles/graphene modified thin film gold electrode. The thin film gold electrode was produced on the polycarbonate (PC) substrate by vacuum sputtering gold plating film, which possessed the advantages of mass production, cost controllable and high sensitivity compared with conventional electrode. Afterwards, gold nanoparticles were introduced onto graphene modified thin film gold electrode to efficiently enhance the electron transfer. The morphology and conductivity of the graphene/gold nanoparticles were characterized by scanning electron microscope, UV-vis spectroscopy, Raman spectroscopy and electrochemical impedance spectroscopy. Under optimal conditions, the sensor demonstrates high sensitivity to detect NF and SC. Results exhibited two linear response of 0.2-80 mu mol L-1 and 280-4800 mu mol L-1 of NF with the detection limit of 0.13 mu mol L-1, and a linear rage of 0.02-2000 mu mol L-1 of SC with the detection limit of 0.0047 mu mol L-1. This sensor was applied successfully for determination of SC in real samples with recoveries of 96.4-105.8%.