ResearchArticle Design of Biotin-Functionalized Luminescent Quantum Dots

Correspondence should be addressed to Hedi Mattoussi, hedimat@ccs.nrl.navy.milReceived 25 June 2007; Accepted 21 December 2007Recommended by Marek OsinskiWe report the design and synthesis of a tetraethylene glycol- (TEG-) based bidentate ligand functionalized with dihydrolipoic acid(DHLA) and biotin (DHLA—TEG—biotin) to promote biocompatibility of luminescent quantum dots (QD’s). This new ligandreadily binds to CdSe—ZnS core-shell QDs via surface ligand exchange. QDs capped with a mixture of DHLA and DHLA—TEG—biotin or polyethylene glycol- (PEG-) (molecular weight average