期刊
ANALYTICA CHIMICA ACTA
卷 1095, 期 -, 页码 61-70出版社
ELSEVIER
DOI: 10.1016/j.aca.2019.10.022
关键词
Nanoporous gold; Amperometric sensors; Electrochemistry; Nanomaterials; Ascorbic acid; Microelectrodes
资金
- Sao Paulo State Research Foundation [FAPESP 2018/08782-1, 201818/21489-1, 2016-07461-1, 2018/09027-2]
- National Council for Scientific and Technological Development [CNPq 401581/2016-0, 303137/2016-9]
- CNPq
- Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [18/09027-2] Funding Source: FAPESP
Tuning the electrocatalytic properties of high surface area porous metallic frameworks like Nanoporous Gold (NPG) by tailoring the structure is a convenient strategy to design electrochemical sensors. Accordingly, an NPG-based sensitive, selective and robust electroanalytical platform was designed for the detection of ascorbic acid (AA) in acidic extracts of Aspergillus fumigatus fungus and Arabidopsis thaliana leaves. NPG films were electrodeposited on a gold microelectrode by potentiostatic electrodeposition and characterized by electron microscopy techniques, which confirmed the morphology and highly porous structure resembling nanowires-type pure gold fractals. The electrodeposition parameters, particularly deposition potential and time, were optimized to achieve large and selective amperometric detection of AA on the NPG modified electrodes. Faster electron transfer kinetics was manifested on the 0.3 V shift in overpotential and remarkable enhancement of the oxidation peak current as compared with bare gold electrode. Amperometric measurements were performed at 0.3 V vs. Ag/AgCl((sat. KCI) )in the highly acidic electrolyte solution employed to extract ascorbate from biological samples and minimize its autoxidation. The sensitivity of conventional Au-microelectrodes was increased about one thousand-fold upon modification with NPG film, reaching 2 nA mu mol(-1) L-1. The detection limit for AA based on a linear current-concentration calibration plot was found to be 2 mu mol L-1. The NPG-based microsensor was demonstrated to be selective, reproducible and stable, and was employed for determinations of AA concentration in highly acidic biological extracts. (C) 2019 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据