Light-induced in situ active tuning of the LSPR of gold nanorods over 90 nm

Abstract

We demonstrate an easy and controllable method for light induced active tuning of the longitudinal surface plasmon resonance (LSPR) of gold nanorods (AuNRs) over ?94 nm. The red-shift of the LSPR can be controlled by varying the time of exposure to a 532 nm laser. The tuning is achieved by photo-induced dissolution of individual AuNRs by sodium dodecyl sulfate (SDS) under continuous illumination. The dissolution of the AuNRs increases the aspect ratio, and consequently the LSPR exhibits a gradual but large red shift. A key feature is that it is possible to selectively tune the LSPR of a specific AuNR in a group while leaving the others totally unaffected. Such controllable, light-induced, post synthesis fine-tuning of the LSPR is useful for tailoring the plasmonic response of individual AuNRs for a wide range of applications