Department of Chemical Science and Technology, Kunming University, Kunming 650214, China.
College of Physics Science and Technology, Kunming University, Kunming 650214, China.
Int J Mol Sci. 2023 May 30;24(11):9480. doi: 10.3390/ijms24119480.
The development of high-performance fluorescence probes has been an active area of research. In the present work, two new pH sensors and based on a halogenated Schiff ligand ( = N, N'-(3,3'-dipropyhnethylamine) bis (3,5-chlorosalicylidene)) with linearity and a high signal-to-noise ratio were developed. Analyses revealed an exponential intensification in their fluorescence emission and a discernible chromatic shift upon pH increase from 5.0 to 7.0. The sensors could retain over 95% of their initial signal amplitude after 20 operational cycles, demonstrating excellent stability and reversibility. To elucidate their unique fluorescence response, a non-halogenated analog was introduced for comparison. The structural and optical characterization suggested that the introduction of halogen atoms can create additional interaction pathways between adjacent molecules and enhance the strength of the interaction, which not only improves the signal-to-noise ratio but also forms a long-range interaction process in the formation of the aggregation state, thus enhancing the response range. Meanwhile, the above proposed mechanism was also verified by theoretical calculations.
高性能荧光探针的发展一直是一个活跃的研究领域。在本工作中，我们开发了两种基于卤化希夫碱配体（ = N，N'-(3,3'-二丙基甲胺)双(3,5-氯水杨醛))的新 pH 传感器 和 ，它们具有线性和高信噪比。分析表明，它们的荧光发射强度呈指数增强，并且在 pH 值从 5.0 增加到 7.0 时会发生明显的色度偏移。传感器在 20 次操作循环后仍能保持初始信号幅度的 95%以上，表现出优异的稳定性和可逆性。为了阐明其独特的荧光响应，引入了非卤化类似物进行比较。结构和光学特性表明，引入卤素原子可以在相邻分子之间创建额外的相互作用途径，并增强相互作用的强度，这不仅提高了信噪比，而且在形成聚集态的过程中形成远程相互作用过程，从而增强了响应范围。同时，上述提出的机制也通过理论计算得到了验证。
