Luminescent Quantum Clusters of Gold as Bio-Labels - Advanced Fluorescence Reporters in Chemistry and Biology - page 352

nontoxic fluorescent Au nanoclusters for the targeted imaging of cancer. There are
also other reports of cell imaging using gold clusters [ 12 , 15 ].
8 Conclusion
Quantum clusters are a new class of nanomaterials composed of very few atoms,
with a core size in the subnanometer regime. Owing to the subnanometer core size,
they cannot possess continuous density of states but have discrete electronic energy
levels. They show “molecule-like” optical transitions in absorption and emission
and are termed as molecular clusters. Because of their high luminescence, photo-
stability, and low metallic content, they hold great promise as ultra bright, biocom-
patible biolabels and light-emitting sources in nanoscale, and hence can be used in
imaging, detection, and so on, in conjunction with therapeutics. Some of these
properties of clusters have been used in bio-labeling experiments. A brief overview
of such efforts is presented. It is expected that many more studies will happen in the
near future.
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