Sugars electrooxidation at glassy carbon electrode decorate with multi-walled carbon nanotubes with nickel oxy-hydroxide

Abstract

The glassy carbon electrode modified with carbon nanotubes decorated with nickel oxy-hydroxide (GC/MWCNT/NiOOH) was used to studied electro-oxidation of glucose, galactose, xylose, arabinose and mannose in alkaline medium. Kinetic parameters such as, charge-transfer coefficient, electrocatalytic rate constant and diffusion coefficient were determined for sugars. Galactose exhibited a higher charge-transfer coefficient (0.37) with a diffusion coefficient of 1.3×10-6 cm2 s-1 and showed the higher electrocatalytic rate constant of 2.1×104 L mol-1 s-1. The modified electrode exhibited a linear response to sugars concentration in the range around of 2.5×10-4 mol L-1 to 5.6×10-3 mol L-1 and limits of detection around of 1.9×10-4 mol L-1 - 4.3×10-4 mol L-1.