Negatively charged luminescent CdSe--ZnS quantum dots (QDs) were
successfully incorporated into novel luminescent glyconanospheres
averaging around 190 nm in diameter through electrostatic interactions
with carboxymethyldextran (CM-dextran) and polylysine. The
glyconanospheres preferably contain as well carboxyl-modified iron oxide
nanocrystals. In addition to electrostatic attraction between the
negatively charged dextran, the negatively charged CdSe--ZnS QDs (and
negatively charged iron oxide nanocrystals, if present), and the
positively charged polylysine, covalent amide bonds were introduced to
cross link the QDs (and negatively charged iron oxide nanocrystals, if
present) with the polysaccharide matrix to further stabilize the
glyconanospheres. The dextran residues on the surface of the nanospheres
show high affinity toward the glucose binding protein-Concanavalin A (Con
A). As a result, these luminescent CdSe--ZnS QD incorporated
glyconanospheres are a useful tool for studying carbohydrate-protein
interactions that are critical steps in bacterial and viral infection.