文献类型：期刊文献

英文题名：Extending the Stokes Shifts of Donor-Acceptor Fluorophores by Regulating the Donor Configuration for In Vivo Three-Photon Fluorescence Imaging

作者：Li, Sifan[1];He, Mubin[2];Jin, Xin[1];Geng, Weihang[2];Li, Chenglin[1];Li, Xinsheng[1];Zhang, Zhiyun[1];Qian, Jun[2];Hua, Jianli[1]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Key Lab Adv Mat, Joint Int Res Lab Precis Chem, Shanghai 200237, Peoples R China;[2]Zhejiang Univ, Coll Opt Sci & Engn, Ctr Opt & Electromagnet Res, Int Res Ctr Adv Photon, State Key Lab Modern Opt Instrumentat, Hangzhou 310058, Peoples R China

年份：2022

卷号：34

期号：13

起止页码：5999

外文期刊名：CHEMISTRY OF MATERIALS

收录：;EI(收录号：20223012419520);WOS:【SCI-EXPANDED(收录号:WOS:000822431900001)】；

语种：英文

外文关键词：Excited states - Fluorescence imaging - Fluorophores - Infrared devices - Photons

摘要：Simple donor-acceptor (D-A) molecules with large Stokes-shifted and bright near-infrared (NIR) emissions are extremely attractive for the high-resolution three-photon fluorescence (3PF) imaging of deep tissues. Herein, we present a new strategy for significantly extending the Stokes shifts of D-A fluorophores, relying on increasing the excited-state structural/electronic relaxation of the donor moiety. The prototype of the D-A structure DPCN, containing the planar donor N,N'-diphenyl-dihydrophenazine (DHP) and the acceptor malononitrile, exhibits normal Stokes-shifted (not approximate to 60 nm) NIR emission. By introducing two methyl groups at the ortho sites of the fused DHP ring of DPCN, DMPCN (methyl-decorated DPCN) is developed with an obviously bent donor unit. Compared to DPCN, DMPCN exhibits significantly blueshifted absorption and keeps NIR luminescence with a large Stokes shift of similar to 200 nm, mainly due to the remarkable bent-to-planar transformation of the donor upon photoexcitation. Additionally, the DMPCN NPs offer enhanced luminescence quantum yields (11%) and three-photon excitation cross sections. More importantly, DMPCN NPs exhibit excellent performances for in vivo 3PF imaging of the cerebrovascular tissue and lipid droplets (LDs) in a fatty liver with a depth of 1200 and 50 mu m, respectively. This research provides a distinct strategy for extending the Stokes shifts of D-A fluorophores, inspiring the utilization of dynamic NIR fluorophores for in vivo 3PF imaging.