title: Rapid covalent ligation of fluorescent peptides to water solubilized quantum dots.
abstract: Water solubilized nanoparticles such as CdSe-ZnS core-shell nanocrystals (quantum dots, QDs) have great potential in bioimaging and sensing applications due to their excellent photophysical properties. However, the efficient modification of QDs with complex biomolecules represents a significant challenge. Here, we describe a straightforward arylhydrazone approach for the chemoselective covalent modification of QDs that is compatible with neutral pH and micromolar concentrations of the peptide target. The kinetics of covalent modification can be monitored spectroscopically at 354 nm in the presence of the QD and average peptide/QD ratios from 2:1 to 11:1 were achieved with excellent control over the desired valency. These results suggest that aniline catalyzed hydrazone ligation has the potential to provide a general method for the controlled assembly of a variety of nanoparticle-biomolecule hybrids.
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Juan B
authors.initials: JB
authors.lastname: Blanco-Canosa
authors.forename: Igor L
authors.initials: IL
authors.lastname: Medintz
authors.forename: Dorothy
authors.initials: D
authors.lastname: Farrell
authors.forename: Hedi
authors.initials: H
authors.lastname: Mattoussi
authors.forename: Philip E
authors.initials: PE
authors.lastname: Dawson
mesh_terms: D000818:Animals; D001547:Benzaldehydes / Q000737:chemistry; D002417:Cattle; D002918:Chymotrypsin / Q000032:analysis; D004337:Drug Carriers / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D045663:Quantum Dots; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D014357:Trypsin / Q000032:analysis; D014867:Water / Q000737:chemistry*
chemical_list: D001547:Benzaldehydes; D004337:Drug Carriers; D005456:Fluorescent Dyes; D010455:Peptides; D014867:Water; D002918:Chymotrypsin; D014357:Trypsin; C032175:benzaldehyde