It is challenging to develop molecular fluorophores in the second near-infrared(NIR-Ⅱ)window with long wavelength emission and high brightness,which can improve the performance of biological imaging.Herein,we report ...It is challenging to develop molecular fluorophores in the second near-infrared(NIR-Ⅱ)window with long wavelength emission and high brightness,which can improve the performance of biological imaging.Herein,we report a molecular engineering approach to afford NIR-Ⅱ fluorophores with these merits based on fused-ring acceptor(FRA)molecules.Dioctyl 3,4-propylenedioxy thiophene(PDOT-C8)is utilized as the bridging donor to replace 3-ethylhexyloxy thiophene(3-EHOT),leading to more than 20 times enhancement of brightness.The nanofluorophores(NFs)based on the optimized CPTIC-4F molecule exhibit an emission peak of 1,110 nm with a fluorescence quantum yield(QY)of 0.39%(QY of IR-26 is 0.050%in dichloroethane as reference)and peak absorption coefficient of 14.5 x 10^4 M^-1·cm^-1 in aqueous solutions,which are significantly higher than those of 3-EHOT based COTIC-4F NFs.It is found that PDOT-C8 can weaken intermolecular aggregation,enhance protection of molecular backbone from water,and decrease backbone distortion,beneficial for the high brightness.Compared with indocyanine green with same injection dose,CPTIC-4F NFs show 10 times higher signal-to-background ratio for whole body vessels imaging at 1,300 nm long pass filters.展开更多
基金Y.L.acknowledges financial supports from the National Natural Science Foundation of China(No.21772084)Fundamental Research Layout of Shenzhen(No.JCY20180504165657443)+2 种基金H.S.thanks the National Natural Science Foundation of China(Nos.11727810,61720106009 and 21603074)the Science and Technology Commission of Shanghai Municipality(No.19JC1412200)for funding support and the ECNU Multifunctional Platform for Innovation(001)and HPC Research Computing Team for providing computational and storage resourcesX.Z thanks the funding supports from the National Natural Science Foundation of China(Nos.91859101,81971744,and U1932107).
文摘It is challenging to develop molecular fluorophores in the second near-infrared(NIR-Ⅱ)window with long wavelength emission and high brightness,which can improve the performance of biological imaging.Herein,we report a molecular engineering approach to afford NIR-Ⅱ fluorophores with these merits based on fused-ring acceptor(FRA)molecules.Dioctyl 3,4-propylenedioxy thiophene(PDOT-C8)is utilized as the bridging donor to replace 3-ethylhexyloxy thiophene(3-EHOT),leading to more than 20 times enhancement of brightness.The nanofluorophores(NFs)based on the optimized CPTIC-4F molecule exhibit an emission peak of 1,110 nm with a fluorescence quantum yield(QY)of 0.39%(QY of IR-26 is 0.050%in dichloroethane as reference)and peak absorption coefficient of 14.5 x 10^4 M^-1·cm^-1 in aqueous solutions,which are significantly higher than those of 3-EHOT based COTIC-4F NFs.It is found that PDOT-C8 can weaken intermolecular aggregation,enhance protection of molecular backbone from water,and decrease backbone distortion,beneficial for the high brightness.Compared with indocyanine green with same injection dose,CPTIC-4F NFs show 10 times higher signal-to-background ratio for whole body vessels imaging at 1,300 nm long pass filters.
