Laboratorio de Química Inorgánica y Organometálica, Departamento de Química Analítica e Inorgánica, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile.
Departamento de Química, Facultad de Ciencias, Universidad de Tarapacá, Arica, Chile.
Luminescence. 2024 Sep;39(9):e4892. doi: 10.1002/bio.4892.
Herein, we describe the design and development of a new cell-permeable aggregation-induced emission (AIE) active 3-ethoxysalicylaldimine-based symmetrical azine molecule HDBE. The synthesized compound underwent comprehensive investigation of different spectroscopic methods, like NMR, mass and single crystal X-ray diffraction analysis. The fluorophore HDBE exhibited the bright orange colour AIE behaviour in THF-HO mixture. The drastic enhancement of emission was achieved upon adding the water to the THF solution of HDBE, with a concentration of 90%. Along with the dynamic light scattering (DLS) and quantum yield measurements, the formation of aggregates was also verified by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. Further, HDBE demonstrated excited state intramolecular proton transfer (ESIPT) characteristics in different polarity of solvents, which was corroborated by absorption, emission and lifetime spectroscopical investigations. The detailed scrutiny of X-ray structure of HDBE displayed the two strong intramolecular hydrogen bonding interactions, while solid-state fluorescent spectra showed dual emission that corresponds to enol and keto form confirming the ESIPT feature. Further, the synthesized AIE molecule was non-toxic and cell-permeable, making it easy to label as a biomarker in live HeLa cells via fluorescent bioimaging. These studies offer a quick and easy way to develop both AIE and ESIPT-coupled molecules for live cell bioimaging applications.
在此，我们描述了一种新型的细胞渗透性聚集诱导发射（AIE）活性 3-乙氧基水杨醛亚胺基对称嗪分子 HDBE 的设计和开发。所合成的化合物经过了包括 NMR、质谱和单晶 X 射线衍射分析在内的多种光谱方法的综合研究。荧光团 HDBE 在 THF-H2O 混合物中表现出明亮的橙色 AIE 行为。当将水加入到 HDBE 的 THF 溶液中时，其发射强度会急剧增强，浓度达到 90%。通过动态光散射（DLS）和量子产率测量，也通过扫描电子显微镜（SEM）和透射电子显微镜（TEM）分析验证了聚集物的形成。此外，HDBE 在不同极性的溶剂中表现出激发态分子内质子转移（ESIPT）特性，这一点通过吸收、发射和寿命光谱学研究得到了证实。对 HDBE 的 X 射线结构的详细研究显示出两个强烈的分子内氢键相互作用，而固态荧光光谱显示出对应于烯醇和酮式的双重发射，证实了 ESIPT 特征。此外，所合成的 AIE 分子具有非毒性和细胞渗透性，使其易于通过荧光生物成像在活 HeLa 细胞中标记为生物标志物。这些研究为活细胞生物成像应用提供了一种快速简便的方法来开发 AIE 和 ESIPT 偶联分子。
