An Improved Sensitivity Non-Enzymatic Glucose Sensor Based on a Nano-Gold Modified Ag Electrode

Abstract

A non-enzymatic glucose sensor based on nano-gold modified Ag electrode was fabricated by two steps. Gold colloid were firstly prepared according to the literature[11] and then a carefully cleaned Ag electrode was dipped into the gold colloid to obtain the non-enzymatic glucose sensor. The structures and morphologies of nano-gold colloid and nano-Au modified electrode were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Vis absorption spectra. The direct electrocatalytic oxidation of glucose in alkaline medium at this modified electrode has been investigated in detail. The result showed that the nano-gold modified electrode had good current response to glucose. The oxidation current was linearly related to the concentration of glucose range frome 0.2 to 175.2μmol/L with a detection limit of 29.5 nmol/L. The nano-gold modified electrode allows highly sensitive, low working potential, fast amperometric sensing of glucose, thus is promising for the future development of non-enzymatic glucose sensors.