Quantum Dot Bioconjugates for Ultrasensitive Nonisotopic Detection
Warren C. W. Chan,
Shuming Nie
*
Highly luminescent semiconductor quantum dots (zinc
sulfide-capped cadmium selenide) have been covalently coupled to
biomolecules for use in ultrasensitive biological detection. In
comparison with organic dyes such as rhodamine, this class of
luminescent labels is 20 times as bright, 100 times as stable against
photobleaching, and one-third as wide in spectral linewidth. These
nanometer-sized conjugates are water-soluble and biocompatible. Quantum
dots that were labeled with the protein transferrin underwent
receptor-mediated endocytosis in cultured HeLa cells, and those dots
that were labeled with immunomolecules recognized specific antibodies
or antigens.
Department of Chemistry, Indiana University, Bloomington, IN
47405, USA.
*
To whom correspondence should be addressed. E-mail: nie{at}indiana.edu