Synthesis of glyconanospheres containing luminescent CdSe-ZnS quantum dots

Negatively charged luminescent CdSe-ZnS quantum dots (QDs) were successfully incorporated into novel luminescent glyconanopsheres averaging 190 nm in diameter through electrostatic interactions with carboxymethyldextran (CM-dextran) and polylysine. In addition to electrostatic attraction between the negatively charged dextran, the negatively charged CdSe-ZnS QDs, and the positively charged polylysine, covalent amide bonds were introduced to cross link the QDs with the polysaccharide matrix to further stabilize the nanospheres. 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.