Controlled synthesis of CdSe and CdSe/CdS core/shell nanoparticles using Gemini surfactant Py-16-10-16 and their bioconjugates with BSA.

CdSe and CdSe/CdS core/shell nanoparticles (NPs) were synthesized by using Gemini surfactant, 1,10-bis(alpha-hexadecyl pyridine) decamethylene dibromide (abbreviated Py-16-10-16), as a soft template. Subsequent analysis revealed that the as-synthesized CdSe NPs and CdSe/CdS core/shell NPs were highly luminescent with quantum yields of 18% and 35%, respectively, compared with Rhodamine 6G (95%). Furthermore, when the nanoparticles were conjugated with bovine serum albumin (BSA) in PBS buffer solution (pH 7.40), the fluorescence intensity of the BSA system was quenched by the addition of CdSe/TGA or CdSe/CdS/TGA NPs, while the fluorescence intensities of CdSe/TGA and CdSe/CdS/TGA NPs were enhanced by the addition of BSA. This enhancement and quenching of the fluorescence intensity by conjugating with BSA could be used to determine the albumin concentration.