Hydrogen evolution assisted deposition of a three-dimensional porous nickel film for the electrocatalytic oxidation of histamine

The authors describe an electrochemical sensor for ultrasensitive voltammetric of histamine (HA) by using a gold electrode that was modified with a film consisting of threedimensional activated microporous nickel (AMPNi/GE). The porous nickel film was deposited on the electrode by hydrogen evolution assisted electrodeposition. The sensor was characterized via scanning electron microscopy, energy dispersive spectrometry, X-ray photoelectron spectroscopy and cyclic voltammetry in order to evaluate its morphology, composition and electrochemical properties. The pore size and wall thickness of the nickel skeleton were tailored by optimizing the concentration of the plating solution, operating temperature, and deposition time. Under the optimum conditions and in 0.1 M NaOH solution at a typical potential of 0.63 V (vs. Ag/AgCl) at a scan rate of 100 mV s(-1,) the sensor gives an analytical response over the 10 nM to 80 mu M HA concentration range, with a 4.2 nM detection limit (S/N = 3) and a 2.38 mu A.mu M-1.cm(-2) sensitivity. The method is sensitive, repeatable, and the sensor is stable.