title: Development of Hybrid Silver-Coated Gold Nanostars for Nonaggregated Surface-Enhanced Raman Scattering.
abstract: In the ongoing search for ever-brighter surface-enhanced Raman scattering (SERS) nanoprobes, gold nanostars (AuNSs) have emerged as one of the best geometries for producing SERS in a nonaggregated state. Despite their high enhancement factor, optical extinction from plasmon-matched nanoparticles can greatly attenuate the overall SERS intensity. Herein, we report the development of a new hybrid bimetallic NS-based platform that exhibits superior resonant SERS (SERRS) properties. In this new nanoplatform, coating AuNSs with a subtotal layer of silver (AuNS@Ag) can further increase their SERRS brightness by an order of magnitude when being interrogated by an off-resonant excitation source. Silica-encapsulated AuNS@Ag nanoprobes were injected intradermally into a rat pelt, where SERRS was readily detected with higher signal-to-noise than nanoprobes prepared from AuNS. Moreover, these off-resonance AuNS@Ag nanoprobes did not cause any gross photothermal damage to tissue, which was observed with the plasmon-matched AuNSs. This novel SERRS-active hybrid nanoprobe exhibits high SERRS brightness and offers promising properties for future applications in sensing and molecular imaging.
authors.affiliation: Fitzpatrick Institute for Photonics, Department of Biomedical Engineering, and Department of Chemistry, Duke University , Durham, North Carolina 27708, United States.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Fales
authors.affiliation: Fitzpatrick Institute for Photonics, Department of Biomedical Engineering, and Department of Chemistry, Duke University , Durham, North Carolina 27708, United States.
authors.forename: Hsiangkuo
authors.initials: H
authors.lastname: Yuan
authors.affiliation: Fitzpatrick Institute for Photonics, Department of Biomedical Engineering, and Department of Chemistry, Duke University , Durham, North Carolina 27708, United States.
authors.forename: Tuan
authors.initials: T
authors.lastname: Vo-Dinh