A Non-Enzymatic Carbohydrate Sensor Based on Multiwalled Carbon Nanotubes Modified with Adsorbed Active Gold Particles

The voltammetric behavior of a glassy carbon electrode modified with multiwalled carbon nanotubes (MWCNTs) and Au particles was studied in alkaline medium towards the electrooxidation of some carbohydrates used as model compounds. The influence of carbohydrate concentration and scan rate on peak potentials, peak currents, etc., observed at the modified electrode was evaluated and critically discussed. The Au particles dispersed into multiwalled carbon nanotubes structures showed favorable electrocatalytic and analytical properties towards the electrooxidation of xylose and glucose molecules. Atomic force microscopy performed on the resulting modified electrode showed a well-efficient 3D distribution of Au active particles having sharp-edged and elongated grains along bundles of the MWCNTs. The three-dimensional MWCNT-Au composite structure of the catalyst act as a promoter to enhance the diffusive character of recorded currents and probably also increases the rate of the heterogeneous electron transfer of the electrooxidation process considered.