Sonoelectrodeposition of gold nanorods at a gold surface – Application for electrocatalytic reduction and determination of nitrofurazone

A sensitive electrochemical sensor was designed based on gold nanorods synthesized by a sonoelectrodeposition method. The morphology and structure of the nanorods were investigated, and voltammetric measurements were performed to study the kinetics of nitrofurazone electroreduction on the nanorod surface in a pH 7.40 phosphate buffer solution. Nitrofurazone was electroreduced on the nanorod surface at lower potentials with a higher rate, compared to a polycrystalline smooth gold surface, through an irreversible process. The results showed that the nanorods can be utilized to fabricate a nitrofurazone sensor. Amperometric and differential pulse voltammetric procedures were applied to the determination of nitrofurazone. Linear dynamic ranges of 50–610 and 3.0–500 μmol L−1 with calibration sensitivities of 2.02 and 0.5 A L mol−1 cm−2, and detection limits of 6.51 and 0.18 μmol L−1 were obtained using amperometry and differential pulse voltammetry (DPV), respectively. DPV method was applied to the analysis of nitrofurazone ointments, and the applicability of the method to direct assays of spiked human serum and urine fluids was investigated.