title: High-resolution three-photon biomedical imaging using doped ZnS nanocrystals.
abstract: Three-photon excitation is a process that occurs when three photons are simultaneously absorbed within a luminophore for photo-excitation through virtual states. Although the imaging application of this process was proposed decades ago, three-photon biomedical imaging has not been realized yet owing to its intrinsic low quantum efficiency. We herein report on high-resolution in vitro and in vivo imaging by combining three-photon excitation of ZnS nanocrystals and visible emission from Mn(2+) dopants. The large three-photon cross-section of the nanocrystals enabled targeted cellular imaging under high spatial resolution, approaching the theoretical limit of three-photon excitation. Owing to the enhanced Stokes shift achieved through nanocrystal doping, the three-photon process was successfully applied to high-resolution in vivo tumour-targeted imaging. Furthermore, the biocompatibility of ZnS nanocrystals offers great potential for clinical applications of three-photon imaging.
authors: Center for Nanoparticle Research, Institute for Basic Science (IBS), and School of Chemical and Biological Engineering, Seoul National University, Seoul, Korea.
authors: Jung Ho
authors: JH
authors: Yu
authors: Seung-Hae
authors: SH
authors: Kwon
authors: Zdeněk
authors: Z
authors: Petrášek
authors: Ok Kyu
authors: OK
authors: Park
authors: Samuel Woojoo
authors: SW
authors: Jun
authors: Kwangsoo
authors: K
authors: Shin
authors: Moonkee
authors: M
authors: Choi
authors: Yong Il
authors: YI
authors: Park
authors: Kyeongsoon
authors: K
authors: Park
authors: Hyon Bin
authors: HB
authors: Na
authors: Nohyun
authors: N
authors: Lee
authors: Dong Won
authors: DW
authors: Lee
authors: Jeong Hyun
authors: JH
authors: Kim
authors: Petra
authors: P
authors: Schwille
authors: Taeghwan
authors: T
authors: Hyeon
mesh_terms: D006801:Humans; D008345:Manganese / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D019047:Phantoms, Imaging; D017785:Photons; D013440:Sulfides / Q000737:chemistry*; D014407:Tumor Cells, Cultured; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D013440:Sulfides; D017967:Zinc Compounds; D008345:Manganese; C031238:zinc sulfide