Electrochemical Behavior of Ascorbic Acid at Copper Germanate Nanowire Modified Electrode

Abstract

Copper germanate (CuGeO 3 ) nanowires are used as the modified materials of glassy carbon electrode to investigate the electrochemical behavior of ascorbic acid. The results show that CuGeO 3 nanowire modified glassy carbon electrode exhibits good performance for the electrochemical detection of ascorbic acid in neutral solution. The intensities of two anodic peaks vary linearly with the concentration of ascorbic acid in the range of 0.01-5 mM and the detection limit is 24 μM and 8.6 μM, respectively at a signal-tonoise ratio of 3, which makes it possible to sensitive detection of ascorbic acid using the CuGeO 3 nanowire modified glassy carbon electrode. The CuGeO 3 nanowire modified electrode exhibits good reproducibility and stability. The good analytical performance makes that the CuGeO 3 nanowires can be used as the electrode modified materials for a wide range of potential application for detecting ascorbic acid.Ascorbic acid (AA, vitamin C) is a kind of important micronutrient and biomicromolecule with many physiological roles. 1, 2 Ascorbic acid is also a powerful antioxidant present in food, beverages and used as a marker chemical in evaluating product quality. 3 Furthermore, great interest has been devoted to ascorbic acid in the cosmetic industry for the production of antiaging treatments. It can protect skin against UVA-induced photoinsult and stimulate collagen and procollagen synthesis as well as human fibolast proliferation. 4, 5 As a result, developing convenient, rapid and facile method for detecting ascorbic acid has been the subject of considerable interest for food, chemistry industry, pharmaceutical quality and safety. [6][7][8][9][10][11][12] Electrochemical method has been used to detect ascorbic acid directly owing to the excellent sensitivity, rapid response, low cost and good convenience. The accurate determination of the concentration is of considerable importance, but the reliable sensing of the ascorbic acid using conventional carbon electrodes has been hindered by the large over-potentials required and electrode fouling by the oxidation products. 12 Direct amperometric detection of ascorbic acid at common electrodes, such as carbon and transition metals is difficult owing to the electrode fouling. 13,14 The amperometric determination of ascorbic acid is based on its electrochemical oxidation process. At bare platinum or glassy carbon electrodes, the reaction proceeds at the potential above +500 mV. However, at chemically modified electrodes (CMEs), the necessary overpotential is lowered substantially. 15 The noble metals, 10 C 60 film, 16 carbon nanotube composite films, 17-20 covalently modified polymers and transition metal compound-based cheap catalysts 21-23 have been employed for the detection of ascorbic acid in the presence of other interferents. Therefore, it is of great significance that a reliable electroanalytical technique might offer greater selectivity, time efficiency and reproducibility than existing methods, such as high-performance liquid chromatography, 24 capillary...

Single crystalline Sr germanate nanowires and their photocatalytic performance for the degradation of methyl blue

“…22,23 In our past research, crystalline calcium germanate nanowires, 24,25 cadmium germanate nanowires 26 and copper germanate nanowires 27 have been synthesized via a simple hydrothermal process by adjusting the metal and salt acetate raw materials and they exhibited good optical and electrochemical properties. 28,29 In this paper, single crystalline Sr germanate nanowires with the orthorhombic SrGeO 3 phase have been synthesized via a simple hydrothermal process using Ge dioxide and Sr acetate as the raw materials. The structure, morphology, size and optical properties of the Sr germanate nanowires have been analyzed by X-ray diffraction (XRD), electron microscopy (EM), Fourier transform infrared (FTIR) and ultraviolet-visible (UV-vis) diffusion reflectance spectra.…”

Electrochemical sensor based on glassy carbon electrode modified with copper vanadate nanobelts for detection of benzoic acid

“…Pei et al [24] reported two anodic CV peaks from the CV curves at the copper vanadate nanobelts modified GCE in 0.1 M KCl solution with 2 mM ascorbic acid appeared at the potential of 0.12 and 0.02 V, respectively. Two pairs of semi-reversible CV peaks were also observed from the CV curves at CuGeO 3 nanowire modified GCE in 0.1 M KCl solution with 2 mM ascorbic acid [25]. The anodic CV peaks appeared at 0.20 and 0.02 V, respectively.…”

Formation of copper vanadate nanobelts and their electrochemical behaviors for the determination of ascorbic acid

“…Two pairs of semi-reversible CV peaks were also observed from the CV curve of ascorbic acid at the ternary copper germanate nanowire modied GCE. 35 Two anodic CV peaks (cvp1, cvp2) were located at +0.20 V and +0.02 V and two cathodic CV peaks (cvp1 0 , cvp2 0 ) were located at +0.07 V and À0.41 V, respectively. The electrochemical CV peaks at the copper germanate nanowire modied GCE were assigned to the oxidation-reduction process (cvp1-cvp1 0 ) and adsorptiondesorption process (cvp2-cvp2 0 ) between ascorbic and dehydroascorbic acid, respectively.…”