Colorimetric Bioassay Using Noble Metal Nanoparticles - From Bioimaging to Biosensors: Noble Metal Nanoparticles in Biodetection - page 52

The key factor in these assays is to control aggregation and
dispersion stages of NPs that are guided by interparticle attractive
and repulsive forces. Thus, control of the charge densities on the
NP surfaces through capping, functionalization, and selection
of suitable media is extremely important to provide highly
selective and sensitive colorimetric assays. Adding hydrophilic
polymers and polyelectrolytes is practical for minimal nonspeciic
interactions, which decrease errors that usually occur when NPs
are applied to biological samples. In order to realize this advantage,
functionalization and stabilization strategies for improving the
selectivity of NPs are required. Because anisotropic Au and Ag NPs
possess high molar absorptivility in the near infrared region, they
also hold great potential for colorimetric bioassays. However, more
advanced functionalization approaches are required.
Acknowledgments
This work was supported by the National Science Council of Taiwan
under contracts NSC 98-2113-M-002-011-MY3 and NSC 99-2113-M-
018-005-MY2. We would like to thank those who provided preprints
that were used in this article.
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