Gold Nanoparticles/Carbon Nanotubes and Gold Nanoporous as Novel Electrochemical Platforms for L-Ascorbic Acid Detection: Comparative Performance and Application

Chemosensors

Federico Tasca¹  Riccarda Antiochia²  Cristina Tortolini³  Cinzia Marchese³  Mary Anna Venneri³ 

[1] Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Sucursal Matucana, Santiago 9170022, Chile;Department of Chemistry and Drug Technologies, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy;Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00166 Rome, Italy;

关键词: L-ascorbic acid;    single walled-carbon nanotubes;    nanoporous gold;    modified electrode;    electrochemical characterization;    electrochemical sensor;   

DOI  :  10.3390/chemosensors9080229

来源: DOAJ

【 摘 要 】

Herein, the effects of nanostructured modifications of a gold electrode surface in the development of electrochemical sensors for L-ascorbic acid detection have been investigated. In particular, a bare gold electrode has been modified by electrodeposition of gold single-walled carbon nanotubes (Au/SWCNTs) and by the formation of a highly nanoporous gold (h-nPG) film. The procedure has been realized by sweeping the potential between +0.8 V and 0 V vs. Ag/AgCl for 25 scans in a suspension containing 5 mg/mL of SWCNTs in 10 mM HAuCl₄ and 2.5 M NH₄Cl solution for Au/SWCNTs modified gold electrode. A similar procedure was applied for a h-nPG electrode in a 10 mM HAuCl₄ solution containing 2.5 M NH₄Cl, followed by applying a fixed potential of −4 V vs. Ag/AgCl for 60 s. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the properties of the modified electrodes. The developed sensors showed strong electrocatalytic activity towards ascorbic acid oxidation with enhanced sensitivities of 1.7 × 10⁻² μA μM⁻¹cm⁻² and 2.5 × 10⁻² μA μM⁻¹cm⁻² for Au/SWCNTs and h-nPG modified electrode, respectively, compared to bare gold electrode (1.0 × 10⁻² μA μM⁻¹cm⁻²). The detection limits were estimated to be 3.1 and 1.8 μM, respectively. The h-nPG electrode was successfully used to determine ascorbic acid in human urine with no significant interference and with satisfactory recovery levels.

【 授权许可】

Unknown