Wednesday, 4 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
The electrochemical determination of glucose concentration through the use of a non-enzymatic system is a priority purposes in recent decades. For this reason, many researchers have focused their studies on the development of sensors of this nature. For this purpose, they have proposed the use of new materials such as metals and metal oxides. In this context, we conducted a study of the synthesis and characterization of the electrical and morphological properties of nickel oxide (II) type - p (p-NiO), all this in order to evaluate it as a possible nonenzymatic sensor glucose molecule. Despite the above, the nickel oxide has a low diffusion rate of charge carriers. Therefore, new synthesis routes leading to a nanostructured oxide is required, so that the photogenerated electrons are accumulated in the vicinity of the surface. This is to facilitate the transfer process of charge per on the recombination. This report shows the results concerning the preparation sonoelectrochemical of NiO nanostructures (NN). Nanostructured NiO layers have been electrochemically grown by ultrasound-assisted anodization of nickel foils (Advent, 99.0%, 0.1 mm) at a potential of 50 V in ethylene glycol (EG; 99.8%, anhydrous), ammonium fluoride (0.5 wt% NH4F) and wt 5.0% DI water. The anodization experiments were carried out using ultrasonic waves (37 kHz, 60 W) and were carried out for 300 s at different temperatures. The above process was carried out using a two-electrode system (flag shaped 1.0 cm2 Ni foil as anode and carbon plate, 22.55 cm2 as cathode; the distance between cathode and anode was kept at 3 cm). Two different nickel substrates have been assayed, i.e.: (i) bare nickel foils, and pre-treated nickel substrates by anodic polarization for 2 hours in a 0.1 M KX (X = F- o Cl-) in aqueous solution at -0.18 V. The resulting NiO nanostructures (NN) will then be named as: NN(w/o) and NN (−0.18 V), respectively. The electrochemical pretreatment process of nickel substrates was carried out using a conventional electrochemical cell with a three-electrode arrangement. As a reference electrode, an Hg/Hg2SO4 (SME, 0.650 V vs. NHE) has been used, and a platinum spiral and a nickel sheet of 1.0 cm2 constituted the counter and working electrode, respectively. The anodized samples are properly washed with distilled water, to remove the occluded ions, and dried in a furnace. Moreover, nanostructured NiO layers obtained were analyzed morphologically by atomic force microscopy (AFM), Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS). The results obtained for nickel oxide as a non-enzymatic glucose sensor are preliminary and are being analyzed by authors.