title: Water-soluble semiconductor nanocrystals cap exchanged with metalated ligands.
abstract: We report a novel method for cap exchange of emissive semiconductor nanocrystals (NCs) using thiol functional ligands metalated with zinc. Utilizing this method, the NCs can be several times brighter and much more resistant to precipitation compared to control samples. This method has been applied using a variety of caps such as dihydrolipoic acid and cysteine. Our data suggest that the improved properties of the metalated cap exchanged NCs are due to a ligand metathesis process occurring at the NC surface where the zinc complex reacts with NC surface bound ligands, gently removing them and replacing them with another cap. Overall, the use of metalated ligands helps resolve many long-standing issues concerning the application of small cap exchanged NCs for biological imaging.
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, United States.
authors.forename: Di
authors.initials: D
authors.lastname: Liu
authors.forename: Preston T
authors.initials: PT
authors.lastname: Snee
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D011232:Chemical Precipitation; D057927:Hydrophobic and Hydrophilic Interactions; D008024:Ligands; D000432:Methanol / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D053758:Nanoparticles / Q000737:chemistry*; D063065:Organophosphonates / Q000737:chemistry; D018036:Selenium Compounds / Q000737:chemistry; D012666:Semiconductors; D012995:Solubility; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D008063:Thioctic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D008024:Ligands; D063065:Organophosphonates; D018036:Selenium Compounds; D013438:Sulfhydryl Compounds; D013440:Sulfides; D017967:Zinc Compounds; D014867:Water; D008063:Thioctic Acid; C015144:dihydrolipoic acid; C058667:cadmium selenide; D015032:Zinc; C031238:zinc sulfide; D000432:Methanol