Zhang Yingying, Zhao Yanliang, Wu Yingnan, Zhao Bing, Wang Liyan, Song Bo
College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China.
School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Feb 15;227:117767. doi: 10.1016/j.saa.2019.117767. Epub 2019 Nov 6.
Lysosome as the typical acidic organelle involved in many biological processes, the dysfunction of its pH would alter many diseases. Small-molecule fluorescent probe has been considered as vital tool for monitoring pH fluctuation in living cells. Herein, a hemicyanine based ratiometric fluorescent probe was synthesized, namely, 2,3-trimethy-3-[2-(dimethyl-amino-4-yl) vinyl]-3H-benzo[e]indole (BiDL), for rapidly detection pH under acidic conditions. BiDL exhibited ratio fluorescence emission (F/F) characteristic with pK 4.25. BiDL showed good linearly response in pH 3.4-4.82, indicating that the probe can be used for quantitative detection pH. The probe also displayed large Stokes shift (112 nm/201 nm) under neutral and acidic conditions, respectively, which could effectively reduce the excitation interference. BiDL had excellent cell membrane permeability, good photo-stability and low toxicity in living cells. The dual-channel confocal fluorescent microscopic ratiometric imaging application of pH in HeLa cells and lysosome were achieved successfully, indicating that BiDL has good potential for investigating lysosome-relevant pathological and physiological processes.
溶酶体作为参与许多生物过程的典型酸性细胞器，其pH值功能障碍会改变多种疾病。小分子荧光探针被认为是监测活细胞中pH值波动的重要工具。在此，合成了一种基于半花菁的比率荧光探针，即2,3-三甲基-3-[2-(二甲基氨基-4-基)乙烯基]-3H-苯并[e]吲哚（BiDL），用于在酸性条件下快速检测pH值。BiDL表现出比率荧光发射（F/F）特性，pK为4.25。BiDL在pH 3.4 - 4.82范围内表现出良好的线性响应，表明该探针可用于pH值的定量检测。该探针在中性和酸性条件下分别表现出较大的斯托克斯位移（112 nm/201 nm），可有效减少激发干扰。BiDL具有优异的细胞膜通透性、良好的光稳定性以及在活细胞中的低毒性。成功实现了pH值在HeLa细胞和溶酶体中的双通道共聚焦荧光显微镜比率成像应用，表明BiDL在研究溶酶体相关病理和生理过程方面具有良好的潜力。
