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Journal of Nanomaterials
Volume 2014, Article ID 765618, 7 pages
http://dx.doi.org/10.1155/2014/765618
Research Article

Seed-Mediated Growth of Gold Nanorods: Limits of Length to Diameter Ratio Control

Department of Polymer and Fiber Engineering, Auburn University, Auburn, AL 36849, USA

Received 11 February 2014; Revised 16 March 2014; Accepted 16 March 2014; Published 14 April 2014

Academic Editor: William W. Yu

Copyright © 2014 Christopher J. Ward et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The effects of the seed reaction conditions on the two-step seed-mediated growth of gold nanorods and the effect of gold and reducing agent content in the growth solution were evaluated. Results indicate that the reaction conditions used to produce the seeds have a significant impact on the aspect ratio of the gold nanorods produced. Increasing the concentration of gold or the reaction temperature in the seed production step results in lower length to diameter (aspect ratio) gold rods. In addition, the amount of prepared seed added to the growth solution impacts the rod aspect ratio, with increasing amounts of seed reducing the aspect ratio. The effects of reducing agent, ascorbic acid (AA), and gold content of the growth solution on the aspect ratio of the produced rods are strongly interrelated. There exists a minimum ascorbic acid to gold concentration below which rods will not form; however, increasing the ratio above this minimum results in shorter rods being formed. Characterization of nanorod growth is performed by UV-vis-NIR spectrophotometry and transmission electron microscopy (TEM).