title: Near-infrared emissive carbon dots for two-photon fluorescence bioimaging.
abstract: Fluorescent probes with both excitation and emission in the near-infrared (NIR) region are highly attractive in the field of bioimaging. Herein, NIR emissive carbon dots (CDs, λmax= 683 nm) capable of excitation with a NIR femtosecond pulse laser (850 nm) are reported for the first time. The NIR CDs also hold a variety of superior features including excellent water dispersibility, narrow emission bands, and high quantum yields (QY = 16.8%). Further studies reveal that the emission of the NIR CDs derives predominantly from the surface molecular state mechanism. More interestingly, the NIR CDs are verified to have very low cytotoxicity and show capabilities for two-photon fluorescence bioimaging. Finally, the NIR CDs are shown to be easily modified with fluorescein isothiocyanate (FITC) and moved into living cells. These findings demonstrate that the as-prepared NIR CDs could not only be potentially employed for deep-tissue two-photon bioimaging, but also used as an effective carrier for delivery of drugs that can't (or hardly) enter into living cells directly.
authors.affiliation: Key Laboratory of Additive Manufacturing Materials of Zhejiang Province & Ningbo Institute of Materials Technology & Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo 315201, P. R. China. linhengwei@nimte.ac.cn and Nano Science and Technology Institute, University of Science and Technology of China, Suzhou 215123, P. R. China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Pan
authors.affiliation: Key Laboratory of Additive Manufacturing Materials of Zhejiang Province & Ningbo Institute of Materials Technology & Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo 315201, P. R. China. linhengwei@nimte.ac.cn.
authors.forename: Shan
authors.initials: S
authors.lastname: Sun
authors.affiliation: Key Laboratory of Additive Manufacturing Materials of Zhejiang Province & Ningbo Institute of Materials Technology & Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo 315201, P. R. China. linhengwei@nimte.ac.cn.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Additive Manufacturing Materials of Zhejiang Province & Ningbo Institute of Materials Technology & Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo 315201, P. R. China. linhengwei@nimte.ac.cn.
authors.forename: Kai
authors.initials: K
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Additive Manufacturing Materials of Zhejiang Province & Ningbo Institute of Materials Technology & Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo 315201, P. R. China. linhengwei@nimte.ac.cn.
authors.forename: Hengwei
authors.initials: H
authors.lastname: Lin
mesh_terms: D002244:Carbon; D005453:Fluorescence; D005456:Fluorescent Dyes; D006801:Humans; D061986:MCF-7 Cells; D017785:Photons; D045663:Quantum Dots; D019265:Spectroscopy, Near-Infrared; D014867:Water
chemical_list: D005456:Fluorescent Dyes; D014867:Water; D002244:Carbon