title: Singlet oxygen production by Peptide-coated quantum dot-photosensitizer conjugates.
abstract: Peptide-coated quantum dot-photosensitizer conjugates were developed using novel covalent conjugation strategies on peptides which overcoat quantum dots (QDs). Rose bengal and chlorin e6, photosensitizers (PSs) that generate singlet oxygen in high yield, were covalently attached to phytochelatin-related peptides. The photosensitizer-peptide conjugates were subsequently used to overcoat green- and red-emitting CdSe/CdS/ZnS nanocrystals. Generation of singlet oxygen could be achieved via indirect excitation through Förster (fluorescence) resonance energy transfer (FRET) from the nanocrystals to PSs, or by direct excitation of the PSs. In the latter case, by using two color excitations, the conjugate could be simultaneously used for fluorescence imaging and singlet oxygen generation. Singlet oxygen quantum yields as high as 0.31 were achieved using 532-nm excitation wavelengths.
authors.affiliation: Department of Chemistry and Biochemistry, California NanoSystems Institute, University of California at Los Angeles, Los Angeles, California 90095, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Tsay
authors.forename: Michael
authors.initials: M
authors.lastname: Trzoss
authors.forename: Lixin
authors.initials: L
authors.lastname: Shi
authors.forename: Xiangxu
authors.initials: X
authors.lastname: Kong
authors.forename: Matthias
authors.initials: M
authors.lastname: Selke
authors.forename: Michael E
authors.initials: ME
authors.lastname: Jung
authors.forename: Shimon
authors.initials: S
authors.lastname: Weiss
mesh_terms: D002735:Chlorophyllides; D031541:Fluorescence Resonance Energy Transfer; D005978:Glutathione / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D017319:Photosensitizing Agents / Q000737:chemistry*; D054811:Phytochelatins; D011166:Porphyrins / Q000737:chemistry; D045663:Quantum Dots; D012395:Rose Bengal / Q000737:chemistry; D026082:Singlet Oxygen / Q000737:chemistry*
chemical_list: D002735:Chlorophyllides; D010455:Peptides; D017319:Photosensitizing Agents; D011166:Porphyrins; D026082:Singlet Oxygen; D012395:Rose Bengal; C062985:phytochlorin; D054811:Phytochelatins; D005978:Glutathione