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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.)

An amperometric sensor for L-cysteine based on nanostructured platform modified with 5,5 `-dithiobis-2-nitrobenzoic acid (DTNB)

Texto completo
Autor(es):
Santhiago, Murilo [1, 2] ; Lima, Phabyanno Rodrigues [3, 2] ; Rodrigues Santos, Wilney de Jesus [1, 2] ; Kubota, Lauro T. [1, 2]
Número total de Autores: 4
Afiliação do(s) autor(es):
[1] Univ Estadual Campinas, Inst Chem, Dept Analyt Chem, BR-13084971 Campinas, SP - Brazil
[2] Univ Estadual Campinas, Inst Nacl Ciencia & Tecnol Bioanalit, BR-13084971 Campinas, SP - Brazil
[3] Univ Fed Alagoas, Inst Quim & Biotecnol, BR-57072970 Maceio, AL - Brazil
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: SENSORS AND ACTUATORS B-CHEMICAL; v. 146, n. 1, p. 213-220, APR 8 2010.
Citações Web of Science: 22
Resumo

In this work, the activation of 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) in situ is proposed, for L-cysteine electrooxidation at low overpotentials. The redox mediator was immobilized in an nanostructured platform containing multi-walled carbon nanotubes (MWCNTs), polyethylenimine (PEI) and gold nanoparticles (GNPs). The optimization of the interface was performed monitoring the R-NO/R-NHOH redox couple in which was electrogenerated in situ by cycling the potential between 0.1 and -0.7 V versus SCE at 100 mV s(-1) The kinetic parameters such as the apparent electron transfer rate constant (k(s)) and the rate constant of the reaction between L-cysteine and DTNB (k(obs)) were evaluated. The electrocatalytic oxidation oft-cysteine was studied by means of cyclic voltammetry, chronoamperometry and amperometry. The sensor presented a linear response range for CyS from 9.0 up to 250 mu molL(-1) with sensitivity of 21 nA mu mol(-1), detection and quantification limits of 2.7 and 9.1 mu mol L(-1) respectively, with a response time of 0.12 s at an applied potential of 0 mV versus SCE. (c) 2010 Elsevier By. All rights reserved. (AU)

Processo FAPESP: 09/08508-8 - Desenvolvimento de sensores químicos a base de siloxanos com impressão molecular para determinação de compostos bioativos
Beneficiário:Wilney de Jesus Rodrigues Santos
Linha de fomento: Bolsas no Brasil - Pós-Doutorado