Photoluminescence of Gold Nanoparticles and Their Applications to Sensing and Cell Imaging - From Bioimaging to Biosensors: Noble Metal Nanoparticles in Biodetection - page 206

poorly understood. A quantitative explanation for the observed
luminescence is missing; it should be investigated. In addition, surface
modiication and crystallinity, which affect the optical properties of
such luminescent Au nanomaterials, are also important issues that
require further study.
Many reports have suggested that these luminescent Au
nanomaterials are promising tools for sensing and intracellular
imaging. Their quantum yields are, however, low when compared
with those of the more popular bioconjugated QDs. In addition, they
are not as photostable as QDs, limiting their use in cell imaging.
Thus, great efforts must be exerted to improve the photostability and
quantum yields of Au nanomaterials, possibly by coating Au NCs and
luminescent Au NPs with biopolymers, polymers, or SiO 2 . In addition,
the preparation of metal nanocomposites, such as luorescent Au/Ag
species, might extend their use in bioassays.
Acknowledgments
Our studies reported herein were supported by the National Science
Council of Taiwan under contract 99-2113-M-019-001-MY2. We
thank those authors who provided preprints or unpublished
material for use in this article, and Huan-Tsung Chang for valuable
comments on the early drafts.
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