Surface Biochemical Modification of Poly(dimethylsiloxane) for Specific Immune Cytokine Response

• Published in: ACS applied bio materials Vol. 4; no. 2; pp. 1307 - 1318
• Main Authors: Laborie, Etienne, Bayle, Fabien, Bouville, David, Smadja, Claire, Dufour-Gergam, Elisabeth, Ammar, Mehdi
• Format: Journal Article
• Language: English
• Published: ACS Publications 23.01.2021
• Subjects: Chemical Sciences; Life Sciences; Silanization, PDMS, Surface Characterization, APTES, Biosensor, TNF-Α, Antibodies, Functionalization
• ISSN: 2576-6422; 2576-6422
• DOI: 10.1021/acsabm.0c01188

Recent evidence suggests that proinflammatory cytokines, such as tumor necrosis factor α (TNF-α), play a pivotal role in the development of inflammatory-related pathologies (covid-19, depressive disorders, sepsis, cancer, etc.,). More importantly, the development of TNF-α biosensors applied to biological fluids (e.g. sweat) could offer non-invasive solutions for the continuous monitoring of these disorders, in particular, polydimethylsiloxane (PDMS)-based biosensors. We have therefore investigated the biofunctionalization of PDMS surfaces using a silanization reaction with 3-aminopropyltriethoxysilane, for the development of a human TNF-α biosensor. The silanization conditions for 50 μm PDMS surfaces were extensively studied by using water contact angle measurements, electron dispersive X-ray and Fourier transform infrared spectroscopies, and fluorescamine detection. Evaluation of the wettability of the silanized surfaces and the Si/C ratio pointed out to the optimal silanization conditions supporting the formation of a stable and reproducible aminosilane layer, necessary for further bioconjugation. An ELISA-type immunoassay was then successfully performed for the detection and quantification of human TNF-α through fluorescent microscopy, reaching a limit of detection of 0.55 μg/mL (31.6 nM). Finally, this study reports for the first time a promising method for the development of PDMS-based biosensors for the detection of TNF-α, using a quick, stable, and simple biofunctionalization process.