Well-controlled synthesis of Au@Pt nanostructures by gold-nanorod-seeded growth.
Pt nanodots were formed on Au nanorods (NRs) by using a simple seed-mediated growth. Their density and distribution on the Au NR can be finely tuned by varying the reaction parameters. At lower Pt/Au ratios, the Pt nanodots mainly appear at endcaps and side edges of the Au rod. At higher Pt/Au ratios, they distribute homogeneously over the whole Au rod. The obtained Pt nanostructure is a single crystal owing to the epitaxial growth of Pt on the Au rod. Due to the unique surface plasmon resonance (SPR) features of the Au NRs, the Au core/Pt shell (Au@Pt) nanostructures also exhibit well-defined and red-shifted longitudinal SPR bands in the visible and near-infrared region. The position and intensity can be regulated by the thickness and amount of the Pt shell. At a thinner Pt thickness, the Au@Pt NRs show higher dielectric sensitivity than the corresponding Au NRs. It thus opens up the potential of Pt nanostructures for SPR-based sensing.
Feng
Lili
L
National Center for Nanoscience and Technology, Zhongguancun, Beiyitiao No. 11, Beijing, 100190 (PR China).
Wu
Xiaochun
X
Ren
Lirong
L
Xiang
Yanjuan
Y
He
Weiwei
W
Zhang
Ke
K
Zhou
Weiya
W
Xie
Sishen
S