Probing the Structure, Composition and Spatial Distribution of Ligands on Gold Nanorods

Published

August 20, 2015

Author(s)

Michael J. A. Hore, Xingchen Ye, Jamie Ford, Yuzhi Gao, Jiayang Fei, Qiong Wu, Stuart J. Rowan, Russell J. Composto, Christopher B. Murray, Boualem Hammouda

Abstract

The structure and size of ligands attached to the surfaces of gold nanorods, such as adsorbed surfactants or grafted polymers, are important considerations that facilitate the use of such nanoparticles in the human body, in advanced materials for energy harvesting, or in devices for single molecule detection. Here, we report small-angle neutron scattering (SANS) measurements from surfactant or polymer coated gold nanorods in solution, which quantitatively determine the location, structure and composition of these surface layers. In addition, by synthesizing gold nanorods using seed crystals which are coated with deuterated cetyltrimethylammonium bromide (dCTAB), we are able to exploit the isotopic sensitivity of SANS to study, for the first time, the transport of surfactant from the seed crystals into the final gold nanorod product, finding that very little exchange of the deuterated with hydrogenated surfactant occurs. Finally, while, we demonstrate that a significant amount of surfactant remains adsorbed to the nanorod surface after the rods are functionalized with a thiol-terminated polymer. These measurements not only provide new insight into the synthesis and functionalization of gold nanorods, but provide a quantitative picture of the structure of grafted polymer and surfactant layers on gold nanorod surfaces which will guide fabrication of plasmonic and biomedical materials.

Citation

Nano Letters

Volume

15

Pub Type

Journals

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Keywords

nanorods, gold nanorod, grafter polymer, core-shell

Citation

Hore, M. , Ye, X. , Ford, J. , Gao, Y. , Fei, J. , Wu, Q. , Rowan, S. , Composto, R. , Murray, C. and Hammouda, B. (2015), Probing the Structure, Composition and Spatial Distribution of Ligands on Gold Nanorods, Nano Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=918296 (Accessed May 10, 2024)