title: Silole-Based Red Fluorescent Organic Dots for Bright Two-Photon Fluorescence In vitro Cell and In vivo Blood Vessel Imaging.
abstract: Robust luminescent dyes with efficient two-photon fluorescence are highly desirable for biological imaging applications, but those suitable for organic dots fabrication are still rare because of aggregation-caused quenching. In this work, a red fluorescent silole, 2,5-bis[5-(dimesitylboranyl)thiophen-2-yl]-1-methyl-1,3,4-triphenylsilole ((MesB)2 DTTPS), is synthesized and characterized. (MesB)2 DTTPS exhibits enhanced fluorescence efficiency in nanoaggregates, indicative of aggregation-enhanced emission (AEE). The organic dots fabricated by encapsulating (MesB)2 DTTPS within lipid-PEG show red fluorescence peaking at 598 nm and a high fluorescence quantum yield of 32%. Upon excitation at 820 nm, the dots show a large two-photon absorption cross section of 3.43 × 10(5) GM, which yields a two-photon action cross section of 1.09 × 10(5) GM. These (MesB)2 DTTPS dots show good biocompatibility and are successfully applied to one-photon and two-photon fluorescence imaging of MCF-7 cells and two-photon in vivo visualization of the blood vascular of mouse muscle in a high-contrast and noninvasive manner. Moreover, the 3D blood vasculature located at the mouse ear skin with a depth of over 100 μm can also be visualized clearly, providing the spatiotemporal information about the whole blood vascular network.
authors.affiliation: College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585.
authors.forename: Guangxue
authors.initials: G
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China.
authors.forename: Bairong
authors.initials: B
authors.lastname: He
authors.affiliation: Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore, 138648.
authors.forename: Chiching
authors.initials: C
authors.lastname: Goh
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585.
authors.forename: Shidang
authors.initials: S
authors.lastname: Xu
authors.affiliation: Centro de Investigaciones en Óptica, A. P. 1-948, 37000, León, Gto, México.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Ramos-Ortiz
authors.affiliation: Centro de Investigaciones en Óptica, A. P. 1-948, 37000, León, Gto, México.
authors.forename: Laura
authors.initials: L
authors.lastname: Aparicio-Ixta
authors.affiliation: College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore, 138648.
authors.forename: Laiguan
authors.initials: L
authors.lastname: Ng
authors.affiliation: College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036, China.|State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China.
authors.forename: Zujin
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China.|Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Ben Zhong
authors.initials: BZ
authors.lastname: Tang
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000502:physiology*; D018360:Crystallography, X-Ray; D003952:Diagnostic Imaging / Q000379:methods*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D061986:MCF-7 Cells; D051379:Mice; D017785:Photons; D012821:Silanes / Q000138:chemical synthesis / Q000737:chemistry*; D012996:Solutions
chemical_list: D005456:Fluorescent Dyes; D012821:Silanes; D012996:Solutions; C540376:silole
keywords: aggregation-enhanced emission; bioimaging; organic dots; silole; two-photon fluorescence