Application of Nanotechnology in Biomedical Sciences by Unknown

Author:Unknown
Language: eng
Format: epub
ISBN: 9789811556227
Publisher: Springer Singapore

5.3 Characteristics Features of Au NPs

The metallic NPs offer a diverse use in biomedical, bio-sensing, imaging, diagnostics, therapeutics and targeted delivery areas. Au NPs, among these, play a preferred role than other metal particles significantly due to their inherent characteristic properties (Eustis and El-Sayed 2006). For instance, the Au NPs are inert (and hence biocompatible) and have high stability. They have a unique optical and electrochemical characteristic that arises due to the phenomenon of Surface Plasmon Resonance. This phenomenon is an optical property usually observed when a beam of light encounters a metal surface and is used to monitor the interaction between two molecules (Jazayeri et al. 2016). It is significantly affected by any alteration in the size or shape of the Au NPs, and the corresponding change in the electron arrangement is reflected in the absorption maxima and color of the dispersion (Jain et al. 2006; McDonnell 2001). For example, the colloidal dispersion containing 13 nm Au NPs presents a characteristic peak at 520 nm and upon an increase in the size of NPs the Surface Plasmon Resonance peak shifts to the longer wavelength observed by the color change of the dispersion from red to the blue (Njoki et al. 2007) (Fig. 5.3). Moreover, the large surface area potentiates their sensitivity, hence contributes significantly towards the application of Au NPs as sensors and detectors (Zeng et al. 2011). The fluorescence studies, approaches such as femtosecond emission (Chen and Katz 2002) and study state investigation are also reported in the literature (Hu et al. 2001). The fluorescent capping groups such as pyrenyl (Thomas and Kamat 2000), fluorenyl (Dubertret et al. 2001), polyoctylthiophenyl (Xu and Yanagi 1999) have been explored to elucidate the possible applications of Au NPs.

Fig. 5.3Representation of the absorption spectrum of Au NPs. As the size of NPs increases, we can observe the shift occurring in the peaks from red to blue. Reprinted with permission from American Chemical Society Copyright (2007) (Njoki et al. 2007)

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.