A highly sensitive sensor for simultaneous determination of ascorbic acid, dopamine and uric acid based on ultra-small Ni nanoparticles

•Small size Ni nanoparticles prepared via a facile and controlled route•The modified electrode was employed for simultaneous determination of AA, DA and UA.•High selectivity, good stability, wide linear range and high sensitivity

A highly sensitive sensor based on carbon-supported Ni nanoparticles (Ni/C) with ultra-small size was prepared for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The electrochemical response showed excellent electrocatalytic activity toward the oxidation of AA, DA and UA with three well defined oxidation peaks and larger peak separation. Meanwhile, using the ultra-small Ni nanoparticles modified electrode with differential pulse voltammetry (DPV) method, the linear response ranges for the determination of AA, DA and UA were 20–2400, 1–55 and 5–180 μM in the coexistence systems of these three species under optimum condition and the detection limits (S/N = 3) were 5, 0.05 and 0.1 μM, respectively. Especially a much higher sensitivity for Ni/C modified electrode compared to other electrodes was also observed. Moreover, satisfactory results were achieved for the determination of AA, DA and UA in vitamin C tablet, DA hydrochloride injection, fetal bovine serum and human urine samples. The results demonstrated that the electrochemical sensor developed from the ultra-small Ni nanoparticles had advantages of high sensitivity and good selectivity for practical applications.

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