Abstract

Ni-doped (0, 2, 5 and 7 wt%)V2O5 nanoparticles were prepared by thermal decomposition method. The as-prepared nanoparticles are characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), Raman spectroscopy, UV-Vis absorption spectroscopy, scanning electron microscopy (SEM) and high resolution-transmission electron microscopy (HR-TEM). The results indicated that the Ni2+ ions are well doped within V2O5 lattices. Compared with pure V2O5, Ni-doped V2O5 (Ni-V2O5) nanoparticles exhibit enhanced dopamine (DA) sensing property. Particularly, 7%Ni-V2O5 nanoplates modified glassy carbon electrode (7%Ni-V2O5/GCE) showed a good response to the DA concentration in the range of 6.6-96.4 mu M with sensitivity of 132 nA mu M-1. The obtained limit of detection (LOD) is 28 nM (S/N = 3). A possible mechanism related to the electrochemical oxidation of DA was proposed. Further, the proposed method was successfully utilized to determine DA in dopamine hydrochloride solution (11-13 mu M) and reasonable results were obtained. The results showed that the 7%Ni-V2O5/GCE exhibits an excellent electrocatalytic activity, good sensitivity, reproducibility, repeatability and long-term stability. (C) 2014 Elsevier B.V. All rights reserved.