Shape trimming and LSPR tuning of colloidal gold nanostars

Herein, we envisioned the post-synthetic shape tailoring/modification of Au nanostars (synthesized by complexation of Polyvinyl pyrrolidone (PVP) in Dimethyl formamide (DMF) under ambient conditions) by simply utilizing NaBr and Br2 for breaking the coordination bonds between PVP and metal, thereby preferentially etching specific crystal facets from Au nanostar spikes and redeposit them at the core, essentially leading to quasi-spherical dimensions with increasing time. Such synergistic tuning was modulated carefully in stabilizing/ arresting the necessary intermediate morphologies by addition of AgNO3 at any point of time, allowing us to exploit the wide range of plasmonic applications in a refined manner.

Automated summary

In this study, the post-synthetic shape tailoring/modification of Au nanostars was achieved by breaking the coordination bonds between PVP and metal using NaBr and Br2. This process selectively etched specific crystal facets from the nanostar spikes and redeposited them at the core, leading to quasi-spherical dimensions over time. The addition of AgNO3 at any point allowed careful modulation of the intermediate morphologies, enabling a refined exploration of the wide range of plasmonic applications.