Toroidal dipole-modulated dipole-dipole double-resonance in colloidal gold rod-cup nanocrystals for improved SERS and second-harmonic generation.

ABSTRACT: Colloidal metal nanocrystals (NCs) show great potential in plasmon-enhanced spectroscopy owing to their attractive and structure-depended plasmonic properties. Herein, unique Au rod-cup NCs, where Au nanocups are embedded on the one or two ends of Au nanorods (NRs), are successfully prepared for the first time via a controllable wet-chemistry strategy. The Au rod-cup NCs possess multiple plasmon modes including transverse and longitudinal electric dipole (TED and LED), magnetic dipole (MD), and toroidal dipole (TD) modulated LED resonances, producing large extinction cross-section and huge near-field enhancements for plasmon-enhanced spectroscopy. Particularly, Au rod-cup NCs with two embedded cups show excellent surface-enhanced Raman spectroscopy (SERS) performance than Au NRs (75.6-fold

SUBMITTER: Kang HS 

PROVIDER: S-EPMC9258465 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature