Aggregation-Driven Controllable Plasmonic Transition of Silica-Coated Gold Nanoparticles with Temperature-Dependent Polymer–Nanoparticle Interactions for Potential Applications in Optoelectronic Devices

Localized surface plasmon resonance (LSPR) effect relies on the shape, size, and dispersion state of metal nanoparticles and can potentially be employed in many applications such as chemical/biological sensor, optoelectronics, and photocatalyst. While complicated synthetic approaches changing shape and size of nanoparticles can control the intrinsic LSPR effect, here we show that controlling interparticle interactions with silica-coated gold nanoparticles (Au@SiO 2 NPs) is a powerful approach, permitting wide range of optical bandwidth of gold nanoparticles with great stability. The interparticle interactions of Au@SiO 2 NPs are controlled through concentration-, temperature-, and time-dependent polymer-induced interactions. The polymer-induced interactions modulate the state of particle dispersion, resulting an effective plasmonic shift by more than 200 nm. We further explore the micros…