Hollow spiky au nanoparticles : single encapsulation, optical properties and potential applications.

Abstract

Hollow spiky gold nanoparticles (s-AuNPs) have been synthesized. The s-AuNPs were further encapsulated by diblock copolymer on the whole or partial surface. By comparing partial and full encapsulation of s-AuNPs with encapsulated fused s-AuNPs, surface-enhanced raman scattering (SERS) and surface plasmon resonance (SPR) could be estimated by the morphology changed from spiky to sphere-like structure. We found that the tips of the s-AuNPs may not increase the SERS signal very well. However, the tips of s-AuNPs are very sensitive to the SPR. Encapsulated s-AuNPs red shifted by 60 nm has shown its potential to be a good plasmonic sensor. By loading organic dye into the cavity of the s-AuNPs, strong SERS signal was obtained. This phenomenon indicated the potential of the hollow s-AuNPs to be a drug delivery carrier. Furthermore, single encapsulation of s-AuNPs and fused s-AuNPs were achieved to give more promising results on SPR and SERS.