Intermolecular hydrogen-bonding as a robust tool toward significantly improving the photothermal conversion efficiency of a NIR-II squaraine dye  

作　　者：Songtao Cai Liuying Wu Yuan Li Soham Samanta Jinying Wang Bing Liu Feihu Wu Kaitao Lai Yingchao Liu Junle Qu Zhigang Yang 

机构地区：[1]Center for Biomedical Photonics&Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province,College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China

出　　处：《Chinese Chemical Letters》2024年第4期310-315,共6页中国化学快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No.61875131);Shenzhen Key Laboratory of Photonics and Biophotonics (No.ZDSYS20210623092006020)。

摘　　要：The photothermal therapy(PTT) has come across as a promising noninvasive therapeutic strategy for tumor treatment. However, low photothermal conversion efficiency(PCE) and hydrophobicity may impede the therapeutic efficacy of organic photothermal agents and an efficient PTT-agent must overcome these two major challenges. In this work, we developed a new strategy to promote higher PCE wherein the intermolecular hydrogen-bonding interaction between the single dye molecule and water facilitated the transformation of the absorbed energy into the heat. A hydrophilic squaraine dye(SCy1) with the second near-infrared region(NIR-II) absorption and extremely low emission were designed to exhibit much higher PCE than that of the analogues of pentamethine-dyes(PCy1, PCy2). The presence of the ‘–O-' at middle of squaric cycle enabled the intermolecular H-bonding formation between the SCy1 and water to promote the energy dissipation channel. Moreover, the introduction of long-chain phenylsulfonate groups helped in to improve the water solubility apart from serving as an additional means of further enhancing PCE through fluorescence quenching. Therefore, SCy1 with a squaraine backbone and long-chain sulfonate moieties revealed outstanding photothermal stability and anti-aggregation activity apart from showing exceptionally high PCE(74%) in water. SCy1 demonstrated excellent therapeutic efficacy when applied in the PTT treatment of tumor-bearing mice under a laser irradiation of 915 nm.

关 键 词：Squaraine-based cyanine Hydrogen bonds High PCE Anti-aggregation Photothermal therapy 

分 类 号：Q503[生物学—生物化学] O641.3[理学—物理化学]