Electrochemical dopamine sensor using a nanoporous gold microelectrode: a proof-of-concept study for the detection of dopamine release by scanning electrochemical microscopy

Author(s)

Catota Saenz, Henry Steven ^{[1, 2]} ; Patricio Hernandez-Saravia, Lucas ^{[1, 3]} ; Selva, Jessica S. G. ^[1] ; Sukeri, Anandhakumar ^[1] ; Javier Espinoza-Montero, Patricio ^[4] ; Bertotti, Mauro ^[1]

Affiliation

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

^[2] Escuela Politec Nacl, Fac Ingn Quim & Agroind, Ladron de Guevara E11-253, POB 17-01-2759, Quito 170525 - Ecuador

^[3] Univ Tarapaca, Dept Chem, Gen Velasquez 1577, Arica, Arica & Parinac - Chile

^[4] Pontificia Univ Catolica Ecuador, Escuela Ciencias Quim, Ave 12 Octubre & Roca, Apartado 17-01-2184, Quito, Pichincha - Ecuador

• Document type: Journal article
• Source: Microchimica Acta; v. 185, n. 8 AUG 2018.
• Web of Science Citations: 19

Abstract

Nanoporous gold (NPG) structures were prepared on the surface of a gold microelectrode (Au-mu E) by an anodization-reduction method. Cyclic voltammetry and field emission scanning electron microscopy were used to study the electrochemical properties and the morphology of the nanostructured film. Voltammetry showed an improved sensitivity for dopamine (DA) oxidation at this microelectrode when compared to a bare gold microelectrode, with a peak near 0.2 V (vs. Ag/AgCl) at a scan rate of 0.1 V s(-1). This is due to the increased surface area and roughness. Square wave voltammetry shows a response that is linear in the 0.1-10 mu mol L-1 DA concentration range, with a 30 nmol L-1 detection limit and a sensitivity of 1.18 mA (mu mol L-1)(-1) cm(-2). The sensor is not interfered by ascorbic acid. The reproducibility, repeatability, long-term stability and real sample analysis (spiked urine) were assessed, and acceptable performance was achieved. The ``proof-of-concept{''} detection of dopamine release was demonstrated by using scanning electrochemical microscopy (SECM) with the aim of future applications for single cell analysis. (AU)

• FAPESP's process: 14/15215-5 - Fabrication and characterization of nanoelectrodes for use in Scanning Electrochemical Microscopy (SECM): fundamental and analytical applications
• Grantee: Sukeri Anandhakumar
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/20776-9 - Fabrication of nanometric probes for the study of biochemical processes by using Scanning Electrochemical Microscopy
• Grantee: Mauro Bertotti
• Support Opportunities: Regular Research Grants