Gold nanorods RM 1

Abstract

Noble metal nanoparticles (NPs), especially Au and Ag, have attracted much attention in recent years particularly due to their localized surface plasmon resonance (SPR) and SPR-related applications. For gold (NPs), various shapes and structures have been successfully synthesized. Gold nanorods (NRs) are among the most studied ones, but the data mining, processing, storing, and sharing related with gold NRs are relatively inadequate. Based on the above considerations, a numeric dataset for the certified reference materials of gold NRs is discussed in this paper. They have two SPR modes, which correspond to the collective electron oscillations along the longitudinal and radial direction of the rod, respectively. The former, denoted as the longitudinal SPR (LSPR), is closely related to the aspect ratio of the nanorod. The latter, denoted as the transverse SPR (TSPR), however, is less sensitive to the aspect ratio. For instance, for a Au NR with a fixed volume (effective radius 13 nm), when the aspect ratio is tuned from 2 to 4.9, the LSPR maximum experiences a large red-shift from 610 nm to 880 nm, while the TSPR wavelength is only slightly affected and blue-shifted from 517 nm to 508 nm. The aspect ratio dependent SPR properties bring in more functionalities to Au NRs, such as tunable surface enhanced Raman scattering (SER) effect, SPR enhanced two photon fluorescence (TPL), nonlinear optical effects and photothermal effects. These properties are potentially useful in ultrasensitive sensing, bio-imaging, photon-triggered drug release and cancer hyperthermia.