Self-organization of gold nanoparticles on silanated surfaces

Abstract

SummaryThe self-organization of monolayer gold nanoparticles (AuNPs) on 3-aminopropyltriethoxysilane (APTES)-functionalized glass substrate is reported. The orientation of APTES molecules on glass substrates plays an important role in the interaction between AuNPs and APTES molecules on the glass substrates. Different orientations of APTES affect the self-organization of AuNps on APTES-functionalized glass substrates. The as grown monolayers and films annealed in ultrahigh vacuum and air (600 °C) were studied by water contact angle measurements, atomic force microscopy, X-ray photoelectron spectroscopy, UV–visible spectroscopy and ultraviolet photoelectron spectroscopy. Results of this study are fundamentally important and also can be applied for designing and modelling of surface plasmon resonance based sensor applications.

Highly sensitive metal-grid strain sensors via water-based solution processing

“…AuNPs were selectively deposited on the grid-patterned APTES layer as the amine group, which is the terminal group of APTES, attaches to AuNPs via electrostatic interactions. [46][47][48] PDMS pre-polymer was cast on the glass using spin coating and then cured. When peeled off the glass, the cured PDMS removes the AuNPs in the form of the desired grid pattern.…”

“…The AuNP solution prepared in advance was injected into the gap between the two plates. 46,48,51 Aer 15 min, the glasses were rinsed with DI water and dried with nitrogen gas. Polydimethylsiloxane (PDMS) pre-polymer (Silgard 184, Dow Corning) with a base-to-curing agent ratio of 10 : 1 was coated on the AuNP-coated glasses with a thickness of 750 mm using a spin-coating technique.…”

Gold Nanoparticle Self-Aggregation on Surface with 1,6-Hexanedithiol Functionalization

“…Gold substrates coated with dithiols, for instance, can efficiently anchor AuNPs [17,18]. The surface of glass, silicon, and indium tin oxide (ITO) pre-coated with (3-aminopropyl)trimethoxysilane (APTES) can efficiently attach AuNPs [19][20][21] as well as NPs made of Ag [22,23], SiO 2 [24], TiO 2 [25,26], Fe 2 O 3 [27,28], or Y-zeolites [29].…”

“…However, obtaining a coating with only single AuNPs well separated from each other is rather difficult to achieve because of the intrinsic presence of self-aggregated AuNPs. Their appearance is associated with the quality of the APTES coating [19]. The smoother the aminosilane monolayer is at the molecular scale, the lower will be the amount of aggregated AuNPs.…”

“…Even with all of these steps, some ethoxy groups of the APTES can remain not completely linked to the surface. This can be improved partially by elevating the APTES solution temperature to~70 • C during substrate silanization [35] or by post-annealing of the APTES-coated substrate at T = 600 • C in vacuum [19]. However, even with these treatments, finding the majority of the -NH 2 groups of the APTES monolayer pointing away from the surface is difficult to achieve [36] and, thus, completely suppressing self-aggregation of AuNPs is impossible.…”