Controlled Self‐Assembly of Metallacycle‐Bridged Gold Nanoparticles for Surface‐Enhanced Raman Scattering

Abstract

Abstract In this work, well‐defined two‐dimensional metallacycles have been successfully employed for the well‐controlled self‐assembly of gold nanoparticles (AuNPs) into discrete clusters such as dimers, trimers, tetramers, pentamers and even hexamers at the water–oil interface for the first time. Furthermore, the modular construction of metallacycle molecules allows precise control of spacing between the gold nanoparticles. Interestingly, it was found that interparticle spacing below 5 nm created by molecular metallacycles in the resultant discrete gold nanoparticle clusters led to a strong plasmon coupling, thus inducing great field enhancement inside the gap between the NPs. More importantly, different discrete clusters with precise interparticle spacing provide a well‐defined system for studying the hot‐spot phenomenon in surface‐enhanced Raman scattering (SERS); this revealed that the SERS effects were closely related to the interparticle spacing.