Self-Assembled Au Nanoparticle Monolayers on Silicon in Two- and Three-Dimensions for Surface-Enhanced Raman Scattering Sensing.

Autor:	Bartschmid T; Department of Chemistry and Physics of Materials, University of Salzburg, Jakob Haringer Strasse 2A, 5020 Salzburg, Austria., Farhadi A; Department of Chemistry and Physics of Materials, University of Salzburg, Jakob Haringer Strasse 2A, 5020 Salzburg, Austria., Musso ME; Department of Chemistry and Physics of Materials, University of Salzburg, Jakob Haringer Strasse 2A, 5020 Salzburg, Austria., Goerlitzer ESA; Institute of Particle Technology, Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany., Vogel N; Institute of Particle Technology, Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany., Bourret GR; Department of Chemistry and Physics of Materials, University of Salzburg, Jakob Haringer Strasse 2A, 5020 Salzburg, Austria.
Jazyk:	angličtina
Zdroj:	ACS applied nano materials [ACS Appl Nano Mater] 2022 Aug 26; Vol. 5 (8), pp. 11839-11851. Date of Electronic Publication: 2022 Aug 15.
DOI:	10.1021/acsanm.2c01904
Abstrakt:	Gold nanoparticle/silicon composites are canonical substrates for sensing applications because of their geometry-dependent physicochemical properties and high sensing activity via surface-enhanced Raman spectroscopy (SERS). The self-assembly of gold nanoparticles (AuNPs) synthesized via wet-chemistry on functionalized flat silicon (Si) and vertically aligned Si nanowire (VA-SiNW) arrays is a simple and cost-effective approach to prepare such substrates. Herein, we report on the critical parameters that influence nanoparticle coverage, aggregation, and assembly sites in two- and three-dimensions to prepare substrates with homogeneous optical properties and SERS activity. We show that the degree of AuNP aggregation on flat Si depends on the silane used for the Si functionalization, while the AuNP coverage can be adjusted by the incubation time in the AuNP solution, both of which directly affect the substrate properties. In particular, we report the reproducible synthesis of nearly touching AuNP chain monolayers where the AuNPs are separated by nanoscale gaps, likely to be formed due to the capillary forces generated during the drying process. Such substrates, when used for SERS sensing, produce a uniform and large enhancement of the Raman signal due to the high density of hot spots that they provide. We also report the controlled self-assembly of AuNPs on VA-SiNW arrays, which can provide even higher Raman signal enhancement. The directed assembly of the AuNPs in specific regions of the SiNWs with a control over NP density and monolayer morphology (i.e., isolated vs nearly touching NPs) is demonstrated, together with its influence on the resulting SERS activity. Competing Interests: The authors declare no competing financial interest. (© 2022 The Authors. Published by American Chemical Society.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu