Electrochemical Sensing of Dopamine, Uric Acid and Ascorbic Acid Using tRGO-TiO<SUB>2</SUB> Nanocomposites

Abstract

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.

Transition metal oxide based non‐enzymatic electrochemical sensors: An arising approach for the meticulous detection of neurotransmitter biomarkers

“…Various TMOs have been reported to composite with rGO for the excellent trace level sensing of DA in presence of the interfering groups. Some of these selective sensors include MnO 2 /rGO by He et al, [29] rGO-Cu 2 O nanocomposite by Sivasubramanian et al, [109] Fe 3 O 4 /rGO nanocomposite by Rani et al [110] and rGO-TiO 2 nanocomposites by Rajamani et al [111] Another alternative for materials compositing with TMOs is highly conducting, tensile, and stable carbon nanotubes (CNT). Mphuthi et al doped phthalocyanine with Fe 3 O 4 and ZnO nanoparticles to couple with CNT [112] and Adekunle et al introduced iron oxide-CNT nanocomposites for the detection of DA.…”

“…[ 110 ] and rGO‐TiO 2 nanocomposites by Rajamani et al. [ 111 ] Another alternative for materials compositing with TMOs is highly conducting, tensile, and stable carbon nanotubes (CNT). Mphuthi et al.…”

Biosynthesis of Copper Oxide (CuO) Nanowires and Their Use for the Electrochemical Sensing of Dopamine

“…When compared to the metal electrodes, nanostructured metal oxide fabricated electrode materials provide some unique electrochemical characteristics and induces higher reaction rates with the exclusion of weakly adsorbed hydrogen species being present on the surface of the oxides [ 18 ]. Various types of nanostructured metal oxides, like ZnO nanowires, RGO-TiO 2 nanocomposites, RuO 2 /CNT, Fe 3 O 4 nanorods/grapheme, Fe 3 O 4 @Au nanoparticles, graphene/SnO 2 , and WO 3 nanoparticles, have been efficiently developed for the determination of DA in the biological samples [ 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Among these electrocatalysts, distinctive properties of copper oxide (CuO) have achieved higher interest, especially in the fields of electrochemical biosensors [ 26 , 27 , 28 , 29 , 30 ].…”

A Facile Synthesis of LaFeO3‐Based Perovskites and Their Application towards Sensing of Neurotransmitters

“…It is found that the 3D rGO showed better performance with a detection limit of 0.17 μM compared to polymer stabilized rGO. In addition various metal,− metal chalcogenide,, metal oxide based nanocomposite have been studied in this regard.…”