Alkoxysilane-Mediated Decoration of Si Nanowires Vertical Arrays with Au Nanoparticles as Improved SERS-Active Platforms

The search for improved transducers to fabricate better-performing (bio)sensors is a challenging but rewarding endeavor aiming to better diagnose and treat diseases. In this paper, we report on the decoration of a dense vertical array of ultrathin silicon nanowires (Si NWs), produced by metal-assist...

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Bibliographic Details
Main Authors: Maria Josè Lo Faro, Ileana Ielo, Dario Morganti, Antonio Alessio Leonardi, Sabrina Conoci, Barbara Fazio, Giovanna De Luca, Alessia Irrera
Format: Article
Language:English
Published: MDPI AG 2023-11-01
Series:International Journal of Molecular Sciences
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Online Access:https://www.mdpi.com/1422-0067/24/23/16685
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Summary:The search for improved transducers to fabricate better-performing (bio)sensors is a challenging but rewarding endeavor aiming to better diagnose and treat diseases. In this paper, we report on the decoration of a dense vertical array of ultrathin silicon nanowires (Si NWs), produced by metal-assisted chemical etching, with 20 nm gold nanoparticles (Au NPs) for surface-enhanced Raman scattering (SERS) applications. To optimize the production of a uniform 3D SERS active platform, we tested different Si NW surface functionalizations with various alkoxysilanes before Au decoration. Scanning electron microscopy investigations confirm that Au NPs decorate both bare and (3-glycidiloxypropyl)trimethoxysilane (GPTMS)-modified Si NWs with a high surface coverage uniformity. The SERS response of the decorated NWs was probed using a model dye system (methylene blue; MB) at 633 and 785 nm excitation wavelengths. The GPTMS-modified NWs present the highest enhancements of 2.9 and 2.6 for the 450 cm<sup>−1</sup> and 1625 cm<sup>−1</sup> peaks under 785 nm excitation and of 10.8 and 5.3 for the 450 cm<sup>−1</sup> and 1625 cm<sup>−1</sup> peaks under 633 nm excitation. These results demonstrate the perspective role of Si NWs decorated with Au NPs as a low-cost 3D SERS platform.
ISSN:1661-6596
1422-0067