Publication Type:

Journal Article


Chemistry - A European Journal, Volume 16, Number 33, p.10103-10112 (2010)



animal, Animals, article, Biolabeling, Body fluids, Bovine, bovine serum albumin, Bovine serum albumins, cation, Cations, cattle, chemistry, Core etching, Enhanced luminescence, Etching, Folic acids, Glutathiones, Gold, Gold compounds, Gold Nanoparticles, Gram quantities, human, Humans, In-cell, Luminescence, Mass spectrometric analysis, Mercaptosuccinic acids, Metal ion sensing, Metal ions, metal nanoparticle, Metal Nanoparticles, Nanoparticles, Organic acids, Organic polymers, Quantum clusters, Quantum yield, Sensors, Serum Albumin, Silver, silver nanoparticles


The synthesis of a luminescent quantum cluster (QC) of gold with a quantum yield of ∼4% is reported. It was synthesized in gram quantities by the core etching of mercaptosuccinic acid protected gold nanoparticles by bovine serum albumin (BSA), abbreviated as Au QC@BSA. The cluster was characterized and a core of Au 38 was assigned tentatively from mass spectrometric analysis. Luminescence of the QC is exploited as a "turn-off" sensor for Cu 2+ ions and a "turn-on" sensor for glutathione detection. Metal-enhanced luminescence (MEL) of this QC in the presence of silver nanoparticles is demonstrated and a ninefold maximum enhancement is seen. This is the first report of the observation of MEL from QCs. Folic acid conjugated Au QC@BSA was found to be internalized to a significant extent by oral carcinoma KB cells through folic acid mediated endocytosis. The inherent luminescence of the internalized Au QC@BSA was used in cell imaging. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


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Cite this Research Publication

M. A. H. Muhammed, Verma, P. K., Pal, S. K., Retnakumari, A., Koyakutty, M., Nair, S. V., and Pradeep, T., “Luminescent quantum clusters of gold in bulk by albumin-induced core etching of nanoparticles: Metal ion sensing, metal-enhanced luminescence, and biolabeling”, Chemistry - A European Journal, vol. 16, pp. 10103-10112, 2010.