title: (110)-exposed gold nanocoral electrode as low onset potential selective glucose sensor.
abstract: A straightforward electrochemical deposition process was developed to grow gold nanostructures, including nanocoral, nanothorn, branched belt, and nanoparticle, on carbon electrodes by reducing HAuCl4 under constant potentials in mixtures containing CTAC and/or NaNO3. Among the nanostructures, the quasi-one-dimensional nanocoral electrode showed the highest surface area. Because of this, it provided excellent electrochemical performances in cyclic voltammetric (CV) studies for kinetic-controlled enzyme-free glucose oxidation reactions. In amperometric studies carried out at 0.200 V in PBS (pH 7.40, 0.100 M), the nanocoral electrode showed the highest anodic current response. It also offered the greatest sensitivity, 22.6 μAmM(-1)cm(-2), an extended linear range, 5.00×10(-2) mM to 3.00×10(1) mM, and a low detection limit, 1.00×10(1) μm among the electrodes investigated in this study. In addition, the glucose oxidation by the nanocoral electrode started at -0.280 V, more negative than the one of using a commercial Au electrode as the working electrode. This is attributed to the presence of exposed Au (110) surfaces on the electrode. The feature was applied to oxidize glucose selectively in the presence of ascorbic acid (AA) and uric acid (UA), common interferences found in physiological analytes. With an applied voltage at -0.100 V, the AA oxidation (started at -0.080 V) can be avoided while the glucose oxidation still provides a significant response.
authors.affiliation: Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan, 30050, ROC.
authors.forename: Ta-Ming
authors.initials: TM
authors.lastname: Cheng
authors.forename: Ting-Kai
authors.initials: TK
authors.lastname: Huang
authors.forename: Huang-Kai
authors.initials: HK
authors.lastname: Lin
authors.forename: Sze-Ping
authors.initials: SP
authors.lastname: Tung
authors.forename: Yu-Liang
authors.initials: YL
authors.lastname: Chen
authors.forename: Chi-Young
authors.initials: CY
authors.lastname: Lee
authors.forename: Hsin-Tien
authors.initials: HT
authors.lastname: Chiu
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D055664:Electrochemical Techniques; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008839:Microelectrodes; D049329:Nanostructures / Q000737:chemistry*; D010084:Oxidation-Reduction; D014527:Uric Acid / Q000737:chemistry*
chemical_list: D014527:Uric Acid; D006046:Gold; D005947:Glucose; D001205:Ascorbic Acid