Ultrasensitive microfluidic electrochemical immunosensor based on electrodeposited nanoporous gold for SOX-2 determination

Autor(es)

Regiart, Matias ^[1] ; Gimenez, Alba Marina ^[2] ; Lopes, Alexandre T. ^[3] ; Carreno, Marcelo N. P. ^[3] ; Bertotti, Mauro ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Chem, Dept Fundamental Chem, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Sch Pharmaceut Sci, Dept Clin & Toxicol Anal, BR-05508000 Sao Paulo, SP - Brazil

^[3] Univ Sao Paulo, Polytech Sch, Dept Elect Syst Engn, BR-05508010 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Analytica Chimica Acta; v. 1127, p. 122-130, AUG 29 2020.
• Citações Web of Science: 0

Resumo

An ultrasensitive and portable microfluidic electrochemical immunosensor for SOX-2 cancer biomarker determination was developed. The selectivity and sensitivity of the sensor were improved by modifying the microfluidic channel. This was accomplished through a physical-chemical treatment to produce a hydrophilic surface, with an increased surface to volume/ratio, where the anti-SOX-2 antibodies can be covalently immobilized. A sputtered gold electrode was used as detector and its surface was activated by using a dynamic hydrogen bubble template method. As a result, a gold nanoporous structure (NPAu) with outstanding properties, like high specific surface area, large pore volume, uniform nanostructure, good conductivity, and excellent electrochemical activity was obtained. SOX-2 present in the sample was bound to the anti-SOX-2 immobilized in the microfluidic channel, and then was labeled with a second antibody marked with horseradish peroxidase (HRP-anti-SOX-2) like a sandwich immunoassay. Finally, an H2O2 + catechol solution was added, and the enzymatic product (quinone) was reduced on the NPAu electrode at +0.1 V (vs. Ag). The current obtained was directly proportional to the SOX-2 concentration in the sample. The detection limit achieved was 30 pg mL(-1), and the coefficient of variation was less than 4.75%. Therefore, the microfluidic electrochemical immunosensor is a suitable clinical device for in situ SOX-2 determination in real samples. (C) 2020 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: 19/06293-6 - Investigações em sistemas biológicos empregando sensores eletroquímicos miniaturizados
• Beneficiário: Daniel Matias Gaston Regiart
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado