US Patent 7597870 - Metal sulfide capped quantum dots

http://www.freepatentsonline.com/7597870.html

Quantum dots are usefully employed as biomarkers but the photoluminescence of qdots can include broadband emission which is disruptive to the identification of compounds. This patent from Drexel University reaches a modification of quantum dots to overcome this problem. Claim 1 reads:

1. A water soluble quantum dot suitable for bioconjugation consisting essentially of: one or more metal sulfides capped with carboxylated molecules.