Preparation of carbon nanotubes supported platinum nanoparticles by an organic colloidal process for nonenzymatic glucose sensing

Multi-walled carbon nanotubes (MWNTs) supported platinum nanoparticles with narrow size distribution were prepared by an organic colloidal process with sodium citrate as the coordination reagent and stabilizer, and ethylene glycol as the reduction reagent. A nonenzymatic glucose sensor with high sensitivity based on the Pt/MWNTs electrode was demonstrated. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were employed to investigate the size distributions and the crystal structure of Pt nanoparticles on the MWNTs. The TEM images show that the Pt nanoparticles with about 2-4 nm in diameter are well dispersed on the MWNTs. The Pt/MWNTs shows high electrocatalytic activity towards the oxidation of glucose in 0.1 M NaOH solution. At +0.5 V, the Pt/MWNTs nanocomposite electrode exhibits linearity in the range of 1 mM to 23 mM (R > 0.998) glucose with a response time of 11.6 s. The detection limit is 50 mu M (S/N = 3). It was demonstrated that the Pt/MWNTs electrode with high electrocatalytic activity to glucose oxidation could find application in nonenzymatic detection of glucose.