Near-infrared(NIR)lights are powerful tools to conduct deep-tissue imaging since NIR-Ⅰ wavelengths hold less photon absorption and NIR-Ⅱ wavelengths serve low photon scattering in the biological tissues compared wit...Near-infrared(NIR)lights are powerful tools to conduct deep-tissue imaging since NIR-Ⅰ wavelengths hold less photon absorption and NIR-Ⅱ wavelengths serve low photon scattering in the biological tissues compared with visible lights.Two-photon fluorescence lifetime microscopy(2PFLM)can utilize NIR-Ⅱ excitation and NIR-Ⅰ emission at the same time with the assistance of a well-designed fluorescent agent.Aggregation induced emission(AIE)dyes are famous for unique optical properties and could serve a large two-photon absorption(2PA)cross-section as aggregated dots.Herein,we report two-photon fluorescence lifetime microscopic imaging with NIR-Ⅱ excitation and NIR-Ⅰ emission using a novel deep-red AIE dye.The AIE-gens held a 2PA cross-section as large as 1.61×10^(4)GM at 1040 nm.Prepared AIE dots had a two-photon fluorescence peak at 790 nm and a stable lifetime of 2.2 ns under the excitation of 1040 nm femtosecond laser.The brain vessels of a living mouse were vividly reconstructed with the two-photon fluorescence lifetime information obtained by our home-made 2PFLM system.Abundant vessels as small as 3.17µm were still observed with a nice signal-background ratio at the depth of 750µm.Our work will inspire more insight into the improvement of the working wavelength of fluorescent agents and traditional 2PFLM.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.61735016,61975172)the Natural Science Foundation of Zhejiang Province of China(No.LR17F050001)+1 种基金the Fundamental Research Funds for the Central Universities of China(No.2020-KYY-511108-0007)the Open Fund of Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregate,South China University of Technology,China(No.2019B030301003).
文摘Near-infrared(NIR)lights are powerful tools to conduct deep-tissue imaging since NIR-Ⅰ wavelengths hold less photon absorption and NIR-Ⅱ wavelengths serve low photon scattering in the biological tissues compared with visible lights.Two-photon fluorescence lifetime microscopy(2PFLM)can utilize NIR-Ⅱ excitation and NIR-Ⅰ emission at the same time with the assistance of a well-designed fluorescent agent.Aggregation induced emission(AIE)dyes are famous for unique optical properties and could serve a large two-photon absorption(2PA)cross-section as aggregated dots.Herein,we report two-photon fluorescence lifetime microscopic imaging with NIR-Ⅱ excitation and NIR-Ⅰ emission using a novel deep-red AIE dye.The AIE-gens held a 2PA cross-section as large as 1.61×10^(4)GM at 1040 nm.Prepared AIE dots had a two-photon fluorescence peak at 790 nm and a stable lifetime of 2.2 ns under the excitation of 1040 nm femtosecond laser.The brain vessels of a living mouse were vividly reconstructed with the two-photon fluorescence lifetime information obtained by our home-made 2PFLM system.Abundant vessels as small as 3.17µm were still observed with a nice signal-background ratio at the depth of 750µm.Our work will inspire more insight into the improvement of the working wavelength of fluorescent agents and traditional 2PFLM.
