Effect of dextran molecular weight on resonance light-scattering of quantum dots modified with dextran and concanavalin A

The reversible aggregation between dextran-conjugated CdSe quantum dots (Dex-CdSe-QDs) and concanavalin A (Con A) was explored based on the specific affinity of polysaccharide for Con A by resonance light-scattering technique. In this study, the aggregation of Dex-CdSe-QDs induced by Con A and sequential dissociation by glucose was determined over a wide range of dextran molecular mass (10–500 kDa). The results demonstrate that the sensitivity of lectin–dextran-modified-QDs interactions increase with dextran molecular mass, and an optimum dextran molecular mass is 500 kDa.