Au nanoparticles anchored on Ni(OH)2 nanowires with multicavities for selective electrochemical detection of dopamine
Au nanoparticles supported on nickel hydroxide nanowires with multicavities (Au/m-Ni(OH)2) were synthesized and used for the enhanced electrochemical sensing of dopamine (DA). m-Ni(OH)2 nanowires were first fabricated based on an anion exchange strategy and then chosen as supports for Au nanoparticles without additional stabilizer and surfactant. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). TEM observations revealed that Au nanoparticles uniformly embedded in the cavities of m-Ni(OH)2 nanowires, with a high dispersion and a narrow size of 2 nm. Electrochemical investigations indicated that the as-prepared sensor exhibited fascinating performance towards the oxidation of DA. The liner range for DA detection was 0.45 M to 1.78 mM with a low detection limit of 0.09 M (S/N=3). Additionally, the DA sensor possessed an excellent selectivity in the potentially interfering substances such as ascorbic acid (AA), uric acid(UA) and glucose (Glu). Therefore, it is expected that the Au/m-Ni(OH)2 nanocomposites could be used as electroactivity materials for developing DA sensor.