Electrochemical application of titanium dioxide nanoparticle/gold nanoparticle/multiwalled carbon nanotube nanocomposites for nonenzymatic detection of ascorbic acid

Titanium dioxide nanoparticle/gold nanoparticle/carbon nanotube (TiO2/Au/CNT) nanocomposites were synthesized, and then characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). A TiO2/Au/CNT nanocomposite-modified glassy carbon (GC) electrode was prepared using the drop coating method and was investigated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), differential pulse voltammetry (DPV), and amperometric current–time response (I-T). The modified material is redox-active. The nonenzymatically detected amount of ascorbic acid (AA) on the TiO2/Au/CNT electrode showed a linear relationship with the AA concentration, for concentrations from 0.01 to 0.08 μM; the sensitivity was 117,776.36 μA · cm−2 · (mM)−1, and the detection limit was 0.01 μM (S/N = 3). The results indicated that the TiO2/Au/CNT nanocomposite-modified GC electrode exhibited high electrocatalytic activity toward AA. This paper describes materials consisting of a network of TiO2, Au, and MWCNTs, and the investigation of their synergistic effects in the detection of AA.