3D-printed electrodes dor sensing: design, characterization, and applications

• Ano de defesa: 2025
• Autor(a) principal: Veloso, William Barros
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: 3D-printed electrodes; Controle local de pH; Electrochemical sensors; Eletrodos impressos em 3D; In situ pH control; IR-laser treatment; Modificação de superfície; Sensores eletroquímicos; Surface modification; Tratamento com laser infravermelho
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/46/46136/tde-29092025-151330/

3D printing has revolutionized the production of three-dimensional objects. Its digitally controlled layer-by-layer material deposition allows for a level of creative freedom that is not achievable with traditional manufacturing methods. The possibility of obtaining conductive parts employing raw materials with electrical properties has paved the way for the current number of 3D-printed electrochemical platforms for sensing applications. However, the lack of fundamental understanding of the limiting electrochemical response aspects, due to the focus on the application step, has limited it to studies of new surface treatment development in similarly designed 3D-printed platforms. This thesis presents a systematic investigation into the development and optimization of 3D-printed electrodes, structured across four chapters. Chapter 1 explores the effect of combining laser ablation and electrochemical activation on enhancing the electrochemical performance of 3D-printed carbon-based electrodes. The treated electrodes exhibited improved redox behavior toward the [Fe(CN)6]3-/4- couple and the electrooxidation of tyrosine, although the system remained quasi-reversible. Chapter 2 addresses this limitation by investigating the role of electric contact resistance in 3D-printed electrodes as a critical factor influencing electrochemical response. Experimental measurements supported by finite element simulations reveal the detrimental impact of high contact resistance, leading to the design of a low-resistance electrode configuration. In Chapter 3, photothermal reduction of gold precursors using infrared laser irradiation is employed to impart electrocatalytic properties to the optimized low-resistance electrodes. The resulting Aumodified electrodes demonstrated high electrocatalytic activity toward glucose oxidation under strong alkaline conditions (0.5 mol L-1 KOH). To extend applicability to neutral media, Chapter 4 introduces a 3D-printed interdigitated electrode array capable of local pH modulation via in situ OH- generation. This configuration enabled glucose oxidation in nonalkaline bulk environments, exemplifying how 3D printing’s geometrical flexibility can be leveraged for electroanalytical applications.