This work reports a graphene-based nonenzymatic electrochemical sensing platform for the detection of dopamine (DA), uric acid (UA), and ascorbic acid (AA). Graphene oxide, synthesized by modified Hummers method, was thermally reduced in an induction furnace at 200 °C in an Ar-H2 atmosphere to obtain thermally reduced graphene oxide (tRGO). Nanocomposites of tRGO-TiO2 were obtained by a hydrothermal method, and were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD). FTIR spectra showed Ti-O-C peaks, indicating covalent linkage between the TiO2 nanoparticles and the reduced graphene oxide sheets. Glassy carbon electrode (GCE) was modified with the nanocomposite (tRGO-TiO2-GCE), and the modified electrode could detect dopamine (DA: 1 to 1000 μM), uric acid (UA: 1 to 900 μM), and ascorbic acid (AA: 10 to 1000 μM) in each other's presence over wide ranges, with adequate separation in peak potentials. Differential pulse voltammetry experiments yielded linear responses with sensitivities of 133.18, 33.96, and 155.59 μA mM-1 cm-2 for DA, UA, and AA, respectively.
cited By 0
A. R. Rajamani, R., K., Krishnan, S., Ramakrishnan, S., Raj, S. M., Kumaresan, D., Kothurkar, N., and Dr. Murali Rangarajan, “Electrochemical sensing of dopamine, uric acid and ascorbic acid using tRGO-TiO2 nanocomposites”, Journal of Nanoscience and Nanotechnology, vol. 15, pp. 5042-5047, 2015.