Authors
Apurve Saini, Rohit Medwal, Saurabh Bedi, Bharat Mehta, Rekha Gupta, Thomas Maurer, Jerome Plain, S. Annapoorni,
Title
Axonic Au Tips Induced Enhancement in Raman Spectra and Biomolecular Sensing
In
Plasmonics
Volume
10
Pages
617–623
Publisher
Springer
Year
2015
Publisher's URL
http://link.springer.com/article/10.1007%2Fs11468-014-9847-4
Indexed by
Abstract
Axonic Au stars with sharp crystalline tips were synthesized via reduction of HAuCl4 capped with cetyl trimethylammonium bromide (CTAB). A seed-mediated method was adopted in which Au seeds were used in the growth solution containing Au+ ions, for initiating the nucleation with CTAB and with ascorbic acid acting as a mild reducing agent. Transmission Electron Microscopy image clearly reveals the synthesis of gold stars. The gold star dispersions display a well-defined optical response as observed by the presence of a sharp surface plasmon resonance centered at 525 nm. The Au stars functionalized with 11-mercaptoundecanoic acid and immobilized with urease showed improved urea-sensing behavior in comparison to pure gold disk in attenuated total reflection surface plasmon resonance (ATR SPR) mode. Surface-enhanced Raman spectroscopy performed using the functionalized Au stars showed a significant enhancement in Raman signals for a wider range of urea concentration (2–20 mg/ml).
Affiliations
Offprint