PEG-interspersed nitrilotriacetic acid-functionalized quantum dots for site-specific labeling of prion proteins expressed on cell surfaces.

A strategy has been put forward to fabricate PEG-interspersed nitrilotriacetic acid (NTA)-functionalized QDs by one-step self-assembly using a mixture of self-synthesized NTA-terminated amphiphilic polymer and 1,2-Distearoyl-sn-Glycero-3-Phosphoethanolamine-N-[Carboxy(Polyethylene Glycol)2000] (DSPE-PEG-COOH). The process was highly reproducible for facile functionalization of QDs via simultaneous self-assembly of biocompatible PEG molecules onto their surface. An optimized molar ratio of NTA-terminated amphiphilic polymer to DSPE-PEG-COOH was used to obtain NTA-functionalized QDs for site-specific labeling of prion proteins (PrP(C)) expressed on cell surfaces. Fabricated NTA-functionalized QDs can be a good candidate used for real-time visualization of PrP(C) in single live cells so as to clarify the nosogenesis of pathogenic scrapie prion protein (PrP(Sc)).