Title: Gold nanoparticles with stable yellow-green luminescence

Authors: Vladimir A. Sinani, Paul Podsiadlo, Jaebeom Lee, Nicholas A. Kotov, Krzysztof Kempa

Addresses: Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA. ' Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA. ' Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA. ' Departments of Chemical Engineering, Materials Science, and Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA. ' Department of Physics, Boston College, Chestnut Hill, MA, 02467, USA

Abstract: Gold nanoparticles (NPs) coated with 6-mercaptopurine-9-β-Dribofuranoside (6-MPR) have been synthesised in aqueous media by replacement of the original citrate stabiliser. Unlike virtually all other Au nano-colloids, the resulting 6-MPR-Au NPs revealed fairly strong photoluminescence with emission maximum at 580 nm and a quantum yield of 6%. The luminescence slowly blue-shifts to 514 nm after several months of aging. Spectroscopic data indicate that the photoluminescence originates from the formation of a complex between gold ions and 6-MPR during the nucleation stage on the surface of the Au NPs, creating the stabilising shell. Au(III), in the presence of pure 6-MPR in aqueous solution has been found to form an Au(6-MPR)2 complex using the Job|s variation method. The presence of Au core considerably enhances the stability of the surface complex, although has little effect on other spectroscopic characteristics. Produced luminescent Au NPs can be used as a convenient model system for biomedical and sensor applications of nanoparticles.

Keywords: gold nanoparticles; biomaterials; purine bases; photoluminescence; nanotechnology; security; nanocolloids; biomedical applications; sensor applications; stable luminescence.

DOI: 10.1504/IJNT.2007.013471

International Journal of Nanotechnology, 2007 Vol.4 No.3, pp.239 - 251

Published online: 01 May 2007 *

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