Probing the ligand exchange kinetics of phenynyl-based ligands on colloidal Au nanoparticles

Abstract

Ligands are the primary tool for stabilizing nanoparticles and surface treatments. Understanding their relative strength and modulating their exchange are the initial steps towards their application. By real-time monitoring of surface-enhanced Raman scattering (SERS), we show that phenynyl ligands could readily bind to colloidal Au nanoparticles giving strong SERS signals. On the basis of the relative exchange ratio, the phenynyl ligands are in general weaker than the strong thiol ligand, and stronger than the polymeric PVP. The method could also be applied to rank the relative strength of phenynyl ligands. We believe that our method provides a general platform for studying ligand affinity. Being a new class of ligands, the understanding of phenynyl ligands would promote their applications in SERS, nanosynthesis, surface treatment, and beyond.