Temperature-Dependent Self-Assembly/Disassembly of Gold Nanoparticles Oligomers

Precisely controlling Au plasmonic coupling aggregates is of fundamental importance for tuning spectroscopic characters, and also is an effective way of access to practical devices. In our present study, we report a new type of amphiphilic gold nanoparticles (AuNPs) with the surfaces modified by thermo-responsive polymer brushes via sequential "grafting to" and "grafting from" reactions. This novel AuNPs can spontaneously self-assemble into AuNPs oligomers such as dimmers and trimmers by taking advantage of the molecular chain reorganization of polymer brushes. Interestingly, AuNPs oligomers can be reversibly disassembled into individually isolated AuNPs by changing temperature. These smart, temperature dependent reversible AuNPs oligomers have great potential applications of plasmonic coupling based sensors and optical imaging.