Dimerization extendsπ-conjugation of electron donor-acceptor structures leading to phototheranostic properties beyond the sum of two monomers  

作　　者：Heng Li Qing Li Ying Gu Mengying Wang Pu Tan Hengtao Wang Liang Han Yulin Zhu Feng He Leilei Tian 

机构地区：[1]Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,P.R.China [2]Department of Chemistry and Shenzhen Grubbs Institute,Southern University of Science and Technology,Shenzhen,P.R.China

出　　处：《Aggregate》2024年第3期429-438,共10页聚集体（英文）

基　　金：National Natural Science Foundation of China,Grant/Award Numbers:22225504,51973089,21975115;Guangdong Provincial Key Laboratory of Catalysis,Grant/Award Number:2020B121201002;Shenzhen Fundamental Research Programs,Grant/Award Numbers:JCYJ20220530113612027,JCYJ20210324120010028;Shenzhen Sci-Tech Fund,Grant/Award Number:KQTD20170810111314625。

摘　　要：Near-infrared(NIR)-IIfluorescence imaging-guided photothermal therapy(PTT)has attracted great research interest,and constructing donor-acceptor(D-A)elec-tronic configurations has become an established approach to lower bandgap and realize NIR-II emission.However,very fewπ-conjugated phototheranostic agents can realize efficient NIR-II guided PTT using a clinically safe laser power density,implying that sufficient photothermal performance is still desired.In addition to the continuously refreshed photothermal conversion efficiency levels,the strategies that focus on enhancing light absorptivity have been rarely discussed and endow a new direction for enhancing PTT.Herein,a dimerizationπ-extension strategy is raised to synthesizeπ-conjugated dimers with A-D-A monomers.We observe that the light absorptivity(ε)of the dimers is strengthened three times owing to the enhanced electronic coupling effect as a result of theπ-conjugation extension,thereby sur-passing the 2-fold increase in chromophore numbers from the monomer to dimers.Thanks to the enhancement in light absorption,the dimers could generate much more photothermal heat than the monomer in in vivo PTT treatments.Therefore,an efficient anti-tumor outcome has been fulfilled by using dimers under a low laser power(0.3 W/cm2).Moreover,the dimers with extendedπ-conjugation struc-tures become more favorable to the radiative excited state decay,thus exhibiting a distinguishing improvement in NIR-II imaging compared with monomer.Collec-tively,due to the improved light absorptivity,the dimers can gain superior NIR-IIfluorescence brightness and photothermal performance over the recently reported material,which goes beyond the monomer in double doses for in vivo applica-tions.All these results prove that dimerization is an effective strategy for designing high-performance phototheranostic materials.

关 键 词：DIMERIZATION NIR-IIfluorescence imaging photothermal therapy safe intensity light π-conjugation extension 

分 类 号：O63[理学—高分子化学]