Gold leaf: From gilding to the fabrication of disposable, wearable and low-cost electrodes

Autor(es)

Ferreira Santos, Mauro Sergio ^[1] ; Ameku, Wilson Akira ^[1] ; Rolf Gutz, Ivano Gebhardt ^[1] ; Longo Cesar Paixao, Thiago Regis ^[1]

Afiliação do(s) autor(es)

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

• Tipo de documento: Artigo Científico
• Fonte: Talanta; v. 179, p. 507-511, MAR 1 2018.
• Citações Web of Science: 0

Resumo

Gold is among the most used materials in electrocatalysis. Despite this, this noble metal is still too expensive to be used in the fabrication of low cost and disposable devices. In the present work, gold-leaf sheets, usually employed in decorative crafts and wedding candies, is introduced as an inexpensive source of gold. Planar-disc and nanoband gold electrodes were simply and easily manufactured by combining gold leaf and polyimide tape. The planar disc electrode exhibited electrochemical behavior similar to that of a commercial gold electrode in 0.2 mol L-1 H2SO4; cyclic voltammetry of a 1 mmol L-1 solution of potassium ferricyanide (K-3(Fe(CN)(6)) in 0.2 mol L-1 KNO3, using this novel electrode, displayed an 80 mV difference between the oxidation and reduction peak potentials. The electrode also delivers promising prospects for the development of wearable devices. When submitted to severe mechanical deformation, this electrode exhibited neither loss of electrical contact nor significant variation in electrode response, even after fifteen bending and/or folding cycles. The thickness of the gold-leaf sheet facilitates the production of nanoband electrodes with behavior similar to that of ultramicroelectrodes. The electrode surface is easily renewed by cutting a thin slice off its end with a razor blade; this process led to limiting currents that were reproducible, presenting a relative standard deviation (RSD) of 3.8% (n = 5). (AU)

• Processo FAPESP: 17/10522-5 - Desenvolvimento de métodos alternativos para fabricação de sensores eletroquímicos em papel
• Beneficiário: Thiago Regis Longo Cesar da Paixão
• Modalidade de apoio: Auxílio à Pesquisa - Regular