Modification of Gold Nanoparticle Composite Nanostructures Using Thermosensitive Core−Shell Particles as a Template

Abstract

We report the formation of novel thermosensitive hybrid core-shell particles via in situ synthesis of gold nanoparticles using thermosensitive core-shell particles as a template. The template core-shell particles, with cores composed mainly of poly(glycidyl methacrylate) (GMA) and shells composed mainly of poly(N-isopropylacrylamide) (PNIPAM), were synthesized in aqueous medium, and functional groups such as thiol groups were incorporated into each particle. We found that these particles containing thiol groups were effective for the in situ synthesis of gold nanoparticles in long-term storage. The obtained hybrid particles exhibited a reversible color change from red to purple, which originated from the surface plasmon resonance of gold nanoparticles and which was temperature-dependent in the range of 25-40 degrees C. In addition to their thermosensitive property, the hybrid particles exhibited the unique characteristic of uniform distribution on a solid substrate. The particles obtained by this approach have potential thermosensitive applications such as in sensors and photonic or electronic devices.

Coating matters: the influence of coating materials on the optical properties of gold nanoparticles

“…In the former case, gold metal ions are fi rst immobilized in the microgel network and subsequently reduced using a chemical agent such as NaBH 4 , which leads to the formation of gold nanoparticles only within the network pores, due to the localization of the AuCl 4 -in relatively higher concentrations within the network by complexation of the gold ions by amines [159] or thiols [160] . In the case of charged microgels, the electrostatic interactions between metal nanoparticles and the charged groups also facilitate the immobilization of metal nanoparticles inside the microgel particles [159] .…”

Thermosensitive core-shell particles as model systems for studying the flow behavior of concentrated colloidal dispersions

“…[14][15][16][17][18][19] A great number of possible applications have been discussed for these systems that include widely separate fields as, e.g., protein adsorption. 20,21 They have also been recently used as a template for the reduction of metal nanoparticles [22][23][24] for applications in catalysis. 23,24 A comprehensive review on the applications was given by Nayak and Lyon.…”

Self-oscillating core/shell microgels: effect of a crosslinked nanoshell on autonomous oscillation of the core

“…In many cases, microgels are composed of poly(N-isopropylacrylamide) (pNIPAm), which is a typical thermosensitive polymer with a lower critical solution temperature of around 31 1C. 5,6 PNIPAm-based microgels can be functionalized by constructing nanocomposites with inorganic nanoparticles [7][8][9][10] for application in more complex biotechnologies and nanotechnologies (for example, drug delivery, 11,12 chemical/biological separation 13,14 and photonic crystals [15][16][17][18] ). In addition, we reported that microgels can show selfoscillation, [19][20][21][22] coupled with the Belousov-Zhabotinsky (BZ) reaction, 23 which is an autonomous and periodic chemical reaction.…”