Thiol-ene click microcontact printing of gold nanoparticles onto silicon surfaces

Abstract

We report a novel process to selectively pattern nanomaterials, specifically gold nanoparticles, onto a silicon surface through “click” chemistry, to consistently and efficiently join together small units through a quick and simple reaction. We employed the UV-initiated thiol-ene reaction, which is used in tandem with microcontact printing. Dithiol-capped nanoparticles were used as a printing ink and were grafted onto ene-terminated Si(100) wafers by pressing a nanoparticle-impregnated poly(dimethylsiloxane) stamp, while irradiating with ultraviolet light to activate a radical initiator. The resulting structures were characterized using scanning electron microscopy and atomic force microscopy.

Direct Bottom-Up In Situ Growth: A Paradigm Shift for Studies in Wet-Chemical Synthesis of Gold Nanoparticles

“…126,172,178−180 These self-assembly processes can be combined with chemically 66,181,182 or physically patterned [35][36][37]49,97,167 substrates, or soft-lithography with nanoparticle inks. 48,64,67,183 The application of physically patterned stamps and substrates to assist in directing the sitespecific attachment of particles is especially popular and includes capillarity-assisted particle assembly 49 or template-assisted selfassembly. [35][36][37]49,97,167 Although there are some reports patterning premade anisotropic particles, such as nanorods 37,184 and triangles, 185 it remains challenging to orient and to arrange anisotropic particles on substrates.…”

“…In contrast to top-down methods, bottom-up colloidal syntheses make it possible to fabricate higher quality single-crystal nanoparticles and to tune morphology rationally. Integrating colloidal particles with substrates typically begins with nanoparticle presynthesis, followed by ligand exchange/modification of the particle surface chemistry and self-assembly. ,,− Uniform films of presynthesized gold nanoparticles can be prepared following ligand exchange and self-assembly via centrifugation, controlled solvent evaporation, ,− and assembly at liquid–liquid ,− and liquid–air interfaces. ,,− These self-assembly processes can be combined with chemically ,, or physically patterned − ,,, substrates, or soft-lithography with nanoparticle inks. ,,, The application of physically patterned stamps and substrates to assist in directing the site-specific attachment of particles is especially popular and includes capillarity-assisted particle assembly or template-assisted self-assembly. − ,,, Although there are some reports patterning premade anisotropic particles, such as nanorods , and triangles, it remains challenging to orient and to arrange anisotropic particles on substrates. While soft lithography methods ( e.g.…”

“…More than simply tuning individual nanoparticles, controlling their positions relative to one another can be used to engineer more complex, cooperative plasmonic responses. When two or more nanoparticles are placed in close proximity, their localized plasmon modes interact, yielding new resonance modes and different distributions of the associated electric field. − Moreover, arrangement of particles into chains or periodic arrays with set spacings can lead to hybridization between the individual plasmon modes and the diffraction modes of the array, producing lattice-plasmon resonances. ,− Even more interesting magnetic, electronic, and optical responses can be engineered via fabrication of different patterns − such as gratings, waveguides, − and chiral superstructures. − Finally, while some colloidal systems can be engineered to exhibit complex plasmonic responses, ,− many devices, sensors, heterogeneous catalysts, and biomedical platforms benefit from incorporating plasmonic nanostructures on or within solid supports such as polymers, − glass, − ,, hydrogels, , semiconductors, − two-dimensional (2D) materials, − and metals …”

Surfaces with Dual Functionality through Specific Coimmobilization of Self-Assembled Polymeric Nanostructures

“…In particular, microcontact printing (μCP) using poly­(dimethylsiloxane) (PDMS) microstamps has served to produce various patterns of self-assembled monolayers, − on which for instance liposomes were immobilized. , The SPAAC reaction has also been used to create surface patterns by μCP of a cyclooctyne linker on an azide-terminated monolayer . In this fashion, liposomes , or inorganic nanoparticles − have also been used as “ink” on PDMS stamps for direct immobilization. However, μCP of polymeric, PDMS-based nanoassemblies has yet to be investigated.…”

“…36,37 The SPAAC reaction has also been used to create surface patterns by µCP a cyclooctyne linker on an azide terminated monolayer. 38 In this fashion, liposomes, 39,40 or inorganic nanoparticles [41][42][43] have also been used as "ink" on PDMS stamps for direct immobilization. However, µCP of polymeric, PDMS based nano-assemblies has yet to be investigated.…”