Development of low-cost planar electrodes and microfluidic channels for applications in capacitively coupled contactless conductivity detection ((CD)-D-4)

Author(s)

Takekawa, Victor Sadanory ^{[1, 2]} ; Marques, Leticia Aparecida ^{[1, 2]} ; Strubinger, Ethan ^{[1, 2, 3]} ; Segato, Thiago Pinotti ^{[1, 2]} ; Bogusz, Jr., Stanislau ^[2] ; Brazaca, Lais Canniatti ^{[1, 2]} ; Carrilho, Emanuel ^{[1, 2]}

Affiliation

^[1] Inst Nacl Ciencia Tecnol Bioanalit INCTBio, Campinas, SP - Brazil

^[2] Univ Sao Paulo, Inst Quim Sao Carlos, 400 Trabalhador Sao Carlense Ave, BR-13566 Sao Carlos, SP - Brazil

^[3] North Carolina State Univ, Dept Chem & Biomol Engn, Raleigh, NC - USA

• Document type: Journal article
• Source: ELECTROPHORESIS; v. 42, n. 16, p. 1560-1569, AUG 2021.
• Web of Science Citations: 0

Abstract

Electrochemical techniques are commonly applied to micro total analysis system (mu TAS) devices mainly due to its high sensitivity and miniaturization capacity. Among many electrochemical techniques, capacitively coupled contactless conductivity detection ((CD)-D-4) stands out for not requiring direct electrode-solution contact, avoiding several problems such as electrolysis, bubble formation, and metal degradation. Furthermore, the instrumentation required for (CD)-D-4 measurements is compact, low cost, and easy to use, allowing in situ measurements to be performed even by nonspecialized personal. Contrarily, the production of metallic electrodes and microchannels adequate for (CD)-D-4 measurements commonly requires specialized facilities and workers, increasing the costs of applying these methods. We propose alternatives to batch manufacture metallic electrodes and polymeric microchannels for (CD)-D-4 analysis using more straightforward equipment and lower-cost materials. Three devices with different dielectric layer compositions and electrode sizes were tested and compared regarding their analytical performance. The constructed platforms have shown a reduction of more than 64% in cost when compared to traditional techniques and displayed good linearity (R-2 >= 0.994), reproducibility (RSD <= 4.07%, n = 3), and limits of detection (<= 0.26 mmol/L) when measuring standard NaCl samples. Therefore, the proposed methods were successfully validated and are available for further (CD)-D-4 applications such as diagnosis of dry-eye syndrome. (AU)

• FAPESP's process: 17/19478-9 - Analytical developments for determination of polychlorinated biphenyls (PCBs) in milk
• Grantee: Stanislau Bogusz Junior
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/19750-3 - Exploring C4D detection for the development of innovative and low-cost microfluidic biosensors
• Grantee: Laís Canniatti Brazaca
• Support Opportunities: Scholarships in Brazil - Post-Doctoral