Assemblies of CdSe and polyethylene glycol derivatives for fluorescent hybrid microspheres

We have synthesized a series of mercapto compounds containing polyethylene glycol (PEG) group for water solubility and bio-compatibility. Those mercapto compounds were used to prepare fluorescent supramolecular assemblies which contain CdSe nanoparticles as the fluorescent moiety and those mercapto compounds as the modifier. Besides PEG group, many other functional groups were also designed in the PEG derivatives such as the vinyl group for polymerization and hydroxyl group and carboxyl group for bio-labeling. Compared with mercaptoacetic acid (MAA) molecules, PEG derivatives can cause red shift in the absorption spectra of the assemblies and enhance the fluorescence intensity. By means of inverse emulsion polymerization, those assemblies can be polymerized into fluorescent hybrid polymeric microspheres which are potential candidates for medical and biotechnological applications.