Coated Chiral Plasmonic Nanorods with Enhanced Structural Stability

Abstract

Several synthesis techniques have emerged for the preparation of chiral metal nanoparticles (NPs) with intrinsic chiral geometrical structures and high optical activity. Chiral plasmonic NPs typically display intricate morphologies terminated by high-energy facets, resulting in limited long-term and thermal stability, which is critical for the development of their applications, e.g., in the biomedical field. Chiral gold nanorods (Au NRs) suffer from loss of structural stability (reshaping), which in turn results in the loss of their optical activity. We carried out a systematic analysis of the stability of chiral Au NRs covered by different protecting shells, against corrosive ions and thermal reshaping. Our findings can be readily extended to other chiral plasmonic NPs with fine structural details and alleviate concerns of instability for various applications under heating and in complex environments.