Design and Characterization of ITO-Covered Resonant Nanopillars for Dual Optical and Electrochemical Sensing

Autor: Luca Tramarin, Rafael Casquel, Jorge Gil-Rostra, Miguel Ángel González-Martínez, Raquel Herrero-Labrador, Ana María M. Murillo, María Fe Laguna, María-José Bañuls, Agustín R. González-Elipe, Miguel Holgado
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Chemosensors, Vol 10, Iss 10, p 393 (2022)
Druh dokumentu: article
ISSN: 10100393
2227-9040
DOI: 10.3390/chemosensors10100393
Popis: In this work we present a dual optical and electrochemical sensor based on SiO2/Si3N4 resonant nanopillars covered with an indium tin oxide (ITO) thin film. A 25–30 nm thick ITO layer deposited by magnetron sputtering acts as an electrode when incorporated onto the nanostructured array, without compromising the optical sensing capability of the nanopillars. Bulk sensing performances before and after ITO deposition have been measured and compared in accordance with theoretical calculations. The electrochemical activity has been determined by the ferri/ferrocyanide redox reaction, showing a remarkably higher activity than that of flat thin films of similar ITO nominal thickness, and proving that the nanopillar system covered by ITO presents electrical continuity. A label-free optical biological detection has been performed, where the presence of amyloid-β has been detected through an immunoassay enhanced with gold nanoparticles. Again, the experimental results have been corroborated by theoretical simulations. We have demonstrated that ITO can be a beneficial component for resonant nanopillars sensors by adding potential electrochemical sensing capabilities, without significantly altering their optical properties. We foresee that resonant nanopillars coated with a continuous ITO film could be used for simultaneous optical and electrochemical biosensing, improving the robustness of biomolecular identification.
Databáze: Directory of Open Access Journals
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