Abstract: Hydrophilic nanoparticles for biological assay were prepared by encapsulating luminescent quantum dots into an amphiphilic polymer via the method of ultrasonic emulsification(O/W). The samples were characterized via photoluminescence(PL) and transmission electron microscope(TEM). The results indicated that the method was simple, time/energy-saving and environmentally friendly. QDs-tagged nanoparticles obtained by this procedure were water-soluble, highly stable and bright in fluorescence emission with a size of 70 nm. After being water-solubilized by amphiphilic polymer, the QDs were labeled by IgGs and used in the biodetection. Spectral analysis showed that on FRET appeared in the water-soluble QDs modified by amphiphilic polymer. The immunofluorescence in vitro indicated that the QDs-IgGs bioconjugates had excellent specific bingding detection ability with nearly non-specific binding. On the basis of the properties QDs-tagged nanoparticles may have great potential for biodetection.

Key words: Quantum dots(QDs), Amphiphilic polymer, Ultrasonic emulsification, Biodetection