Enhanced Non-enzymatic amperometric sensing of glucose using Co(OH)2 nanorods deposited on a three dimensional graphene network as an electrode material
1.School of Mechanical Engineering,Yonsei University,Seoul,Republic of Korea;2.Institute of Physics and Applied Physics,Yonsei University,Seoul,Republic of Korea
Abstract:
We report on the synthesis of cobalt dihydroxide [Co(OH)2] nanorods and their deposition on a 3-dimensional graphene network via chemical bath deposition. The structural characterization reveals deposited Co(OH)2 to consist of flower-like nanorods on a 3-dimensional graphene foam. The nanocomposite was used for glucose sensing by electrocatalytic oxidation of glucose in 1 M KOH solution. Cyclic voltammetry and amperometric studies revealed a high sensitivity for glucose (3.69 mA mM?1 cm?2) and a 16 nM detection limit. The nanocomposite offers a large effective surface (11.4 cm2) and is very selective for glucose over potentially interfering materials such as dopamine, ascorbic acid, lactose, fructose and urea, not the least due to a relatively low working potential of 0.6 V (vs. Ag/AgCl). The high sensitivity, low detection limit and very good selectivity of free-standing nanocomposite electrodes are attributed to the synergistic effect of (a) the good electrocatalytic activity of the NRs, and (b) the large surface area with high conductivity offered by the 3D graphene foam.