Gold Nanostar Synthesis with a Silver Seed Mediated Growth Method |
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Authors: | Zurab Kereselidze Victor H Romero Xomalin G Peralta Fidel Santamaria |
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Institution: | Department of Physics and Astronomy, The University of Texas at San Antonio;Centro de Investigaciones en Optica A. C.;Department of Biology and Neurosciences Institute, The University of Texas at San Antonio |
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Abstract: | The physical, chemical and optical properties of nano-scale colloids depend on their material composition, size and shape 1-5. There is a great interest in using nano-colloids for photo-thermal ablation, drug delivery and many other biomedical applications 6. Gold is particularly used because of its low toxicity 7-9. A property of metal nano-colloids is that they can have a strong surface plasmon resonance 10. The peak of the surface plasmon resonance mode depends on the structure and composition of the metal nano-colloids. Since the surface plasmon resonance mode is stimulated with light there is a need to have the peak absorbance in the near infrared where biological tissue transmissivity is maximal 11, 12.We present a method to synthesize star shaped colloidal gold, also known as star shaped nanoparticles 13-15 or nanostars 16. This method is based on a solution containing silver seeds that are used as the nucleating agent for anisotropic growth of gold colloids 17-22. Scanning electron microscopy (SEM) analysis of the resulting gold colloid showed that 70 % of the nanostructures were nanostars. The other 30 % of the particles were amorphous clusters of decahedra and rhomboids. The absorbance peak of the nanostars was detected to be in the near infrared (840 nm). Thus, our method produces gold nanostars suitable for biomedical applications, particularly for photo-thermal ablation. |
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Keywords: | Bioengineering Issue 59 thermal ablation surface plasmon resonance nanoparticle nanotechnology silver seeds |
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