Maximizing surface reactivity: The impact of electrochemical oxidation as a polydopamine modification step

Author(s)

Teixeira, Jean Valdir Uchoa ; Dias, Leonardo Francisco Gonsalves ; Guerra, Nayrim Brizuela ; Capelin, Guilherme Ribeiro ; Mastelaro, Valmor Roberto ; Lisboa-Filho, Paulo Noronha

• Document type: Journal article
• Source: COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS; v. 706, p. 14-pg., 2025-02-05.

Abstract

Melanin-based materials are highly versatile and widely utilized across various industries, thanks to their customizable surface properties and excellent biocompatibility. Dopamine, a well-studied precursor, has the remarkable ability to self-oxidize and form melanin-like compounds. This molecule can be tailored using cations during the oxidation process or via the chelation of hydroxyl groups in the final material. In order to explore the adaptability of dopamine-based melanin materials, our research focuses on producing particles using an innovative double-step process. The first oxidation is catalyzed by Y 3 + in an electrochemical process, followed by further cyclization in a basic medium. We examined the resulting products to gauge the impact of the process on the final molecular arrangement and chelation capacity by utilizing Fe2+ as a cation probe. Surface reactivity was assessed using voltammetry techniques and electrochemical impedance spectroscopy. The results clearly indicate significant improvements in the molecular arrangement, demonstrating that the double-step process delivers higher material stability and superior surface reactivity compared to the conventional alkali self-oxidation method. (AU)

• FAPESP's process: 21/09207-3 - Fabrication of electrochemical transistors based on doped melanin with improved ionic and electronic conductivity
• Grantee: Nayrim Brizuela Guerra
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC