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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Amperometric microsensor based on nanoporous gold for ascorbic acid detection in highly acidic biological extracts

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Autor(es):
Kumar, Abhishek [1] ; Furtado, Vinicius L. [1] ; Goncalves, Josue M. [1] ; Bannitz-Fernandes, Renata [2] ; Netto, Luis Eduardo S. [2] ; Araki, Koiti [1] ; Bertotti, Mauro [1]
Número total de Autores: 7
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Inst Chem, Dept Fundamental Chem, Av Prof Lineu Prestes 748, BR-05513970 Sao Paulo, SP - Brazil
[2] Univ Sao Paulo, Inst Biosci, Dept Genet & Evolutionary Biol, Rua Matao 321, BR-05508090 Sao Paulo, SP - Brazil
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Analytica Chimica Acta; v. 1095, p. 61-70, JAN 25 2020.
Citações Web of Science: 0
Resumo

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. (AU)

Processo FAPESP: 18/08782-1 - Sensores químicos miniaturizados e integrados: novas plataformas de fabricação para aplicações biológicas, clínicas e ambientais
Beneficiário:Mauro Bertotti
Linha de fomento: Auxílio à Pesquisa - Temático
Processo FAPESP: 18/21489-1 - Nanotecnologia supramolecular: design, materiais e dispositivos
Beneficiário:Henrique Eisi Toma
Linha de fomento: Auxílio à Pesquisa - Temático
Processo FAPESP: 18/09027-2 - Desenvolvimento de sensores eletroquímicos para detecção de ascorbato no fungo patógeno humano Aspergillus fumigatus
Beneficiário:Vinícius Lima Furtado
Linha de fomento: Bolsas no Brasil - Iniciação Científica