title: Core/shell quantum dots with high relaxivity and photoluminescence for multimodality imaging.
abstract: A series of core/shell CdSe/Zn1-xMnxS nanoparticles were synthesized for use in dual-mode optical and magnetic resonance (MR) imaging techniques. Mn2+ content was in the range of 0.6-6.2% and varies with the thickness of the shell or amount of Mn2+ introduced to the reaction. These materials showed high quantum yield (QY), reaching 60% in organic solvent. Water-soluble nanoparticles were obtained by capping the core/shell particles with amphiphilic polymer, and the QY values in water reached 21%. These materials also demonstrated high relaxivity with r1 values in the range of 11-18 mM-1 s-1 (at room temperature, 7 T). Both optical and MR imaging were performed on nanoparticles in aqueous solution and applied to cells in culture. The results showed that the QY and manganese concentration in the particles was sufficient to produce contrast for both modalities at relatively low concentrations of nanoparticles.
authors.affiliation: Department of Chemistry, and Department of Biomedical Engineering, University of California, Davis, CA 95616, USA.
authors.forename: Shizhong
authors.initials: S
authors.lastname: Wang
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Jarrett
authors.forename: Susan M
authors.initials: SM
authors.lastname: Kauzlarich
authors.forename: Angelique Y
authors.initials: AY
authors.lastname: Louie
mesh_terms: D000818:Animals; D002460:Cell Line; D004578:Electron Spin Resonance Spectroscopy; D008163:Luminescent Measurements; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D053758:Nanoparticles; D010777:Photochemistry; D045663:Quantum Dots; D014961:X-Ray Diffraction