title: Real-time monitoring for the morphological variations of single gold nanorods.
abstract: The morphological characteristics of metal nanoparticles, particularly the shape, play an essential role in the optical, physical and chemical properties. In this work, we reported a transverse etching process to investigate the morphological variations of single gold nanorods (GNRs). Dark-field microscopy and Rayleigh scattering spectroscopy were used as complementary technologies to track the transverse etching process. Dark-field imaging with high spatial and temporal resolution could easily monitor the transverse etching process of GNRs in situ and in real time. Interactions between the scattering spectrum and the morphological variations were judiciously calculated within the dipole approximation by the Drude function. The calculated peak shift of GNRs (Δλmax = 17 nm) was obtained via the ratio of the long axis and short axis (aspect ratio) of GNRs from transmission electron microscopy. The average scattering peak shift (Δλmax = 22 nm) from Rayleigh scattering spectroscopy was in good agreement with the calculated peak shift. Monitoring the morphological variations of single GNRs enables us to track the transverse etching of GNRs at arbitrary time. This promises to be a useful method for the study of different nanomaterials and their spectral properties.
authors.affiliation: Key Laboratory for Advanced Materials & Department of Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China. ytlong@ecust.edu.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Xie
authors.forename: Chao
authors.initials: C
authors.lastname: Jing
authors.forename: Wei
authors.initials: W
authors.lastname: Ma
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Ding
authors.forename: Andrew James
authors.initials: AJ
authors.lastname: Gross
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Long