Fluorescence Quenching of Human Serum Albumin by Polyacrylamide Grafted onto Sodium Alginate Capped ZnS Quantum Dots

: The synthesis of water-soluble quantum dots (QDs) is of crucial importance for nanobiotechnology. A polyacrylamide grafted onto sodium alginate was successfully synthesized and employed for coating ZnS QDs in aqueous solution. The as-obtained QDs were characterized by atomic- force microscopy (AFM). After that, the interaction of coated QDs with human serum albumin (HSA) were investigated under the simulative physiological conditions. Fluorescence analysis at different temperatures revealed the gradual quenching of both proteins by titration with coated QDs. The binding sites number and binding constant were calculated at various temperatures.