Separation of Gold Nanorods Using Density Gradient Ultracentrifugation
),
Xiaoming Sun(
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High quality gold nanorods (NRs) with a monodisperse size and aspect ratio are essential for many applications. Here, we describe how nearly monodisperse gold NRs can be separated from polydisperse samples using density gradient ultracentrifugation. Size and dimension analysis by transmission electron microscopy (TEM) and absorption spectroscopy revealed that the Au NRs were separated mainly as a function of their aspect ratio. The surface-enhanced Raman scattering (SERS) activity of Au NRs with lower aspect ratio is notably stronger than that of NRs with higher aspect ratio under 633 nm laser excitation, due to the size-dependent absorption of the longitudinal plasmon band. The separation approach provides a method to improve the quality of NRs produced by large scale synthetic methods.
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Separation of Gold Nanorods Using Density Gradient Ultracentrifugation
), Xiaoming Sun(
)
Abstract
High quality gold nanorods (NRs) with a monodisperse size and aspect ratio are essential for many applications. Here, we describe how nearly monodisperse gold NRs can be separated from polydisperse samples using density gradient ultracentrifugation. Size and dimension analysis by transmission electron microscopy (TEM) and absorption spectroscopy revealed that the Au NRs were separated mainly as a function of their aspect ratio. The surface-enhanced Raman scattering (SERS) activity of Au NRs with lower aspect ratio is notably stronger than that of NRs with higher aspect ratio under 633 nm laser excitation, due to the size-dependent absorption of the longitudinal plasmon band. The separation approach provides a method to improve the quality of NRs produced by large scale synthetic methods.
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Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (NSFC), Beijing Natural Science Foundation (No. 2102033), the Program for New Century Excellent Talents in Universities, and the 973 Program (No. 2009CB939801).
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