Mohanty Patitapaban, Dash Pragyan P, Mishra Swagatika, Behura Rubi, Behera Priyatama, Mishra Monalisa, Sahoo Harekrushna, Sahoo Suban K, Jali Bigyan R
Department of Chemistry, Veer Surendra Sai University of Technology, Burla, Sambalpur 768018 Odisha, India.
Department of Life Science, National Institute of Technology, Rourkela 769008 Odisha, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Oct 5;338:126221. doi: 10.1016/j.saa.2025.126221. Epub 2025 Apr 11.
Sensitive and reliable fluorescence chemosensors for the monitoring of Hg levels are very important for the protection of environment and living systems. Herein, a simple thiourea-based irreversible fluorescence and colorimetric chemosensor L has been devised and characterised by various spectral analysis. Probe L selectively detects Hg ion due to the binding site-signalling strategy, where the pyridine ring serves as the fluorophore unit and the thiourea moiety serves as the coordinating site. The incorporation of Hg ions to a DMSO solution of L shows substantial alterations in the UV-Vis spectrum and fluorescence spectra. This alteration in absorption as well as fluorescence profile refers to the increase in the intra-molecular charge transfer (ICT) and chelation-induced enhanced fluorescence (CHEF) of L-Hg complex. For the Hg ion, the detection limit is reached up to 2.5 × 10 M, which is calculated from the IUPAC formula C = 3σ/slope. The Job's plot reveals a 1:1 binding stoichiometry between L and Hg. Applying Benesi-Hildebrand equation, the binding constant for the L-Hg complex was estimated as 7.54 × 10 M. To validate the mechanism involved in the formation of L-Hg complex, the DFT and TD-DFT calculations were performed in the gas phase. L has been used well to identify Hg ions in soil samples over a wide pH range. The receptor L was also applied for cell imaging study.
用于监测汞含量的灵敏且可靠的荧光化学传感器对于保护环境和生物系统非常重要。在此，设计了一种基于硫脲的简单不可逆荧光和比色化学传感器L，并通过各种光谱分析对其进行了表征。探针L通过结合位点信号策略选择性地检测汞离子，其中吡啶环作为荧光团单元，硫脲部分作为配位位点。将汞离子加入到L的二甲基亚砜溶液中会导致紫外可见光谱和荧光光谱发生显著变化。这种吸收和荧光光谱的变化是指L-Hg配合物的分子内电荷转移（ICT）和螯合诱导增强荧光（CHEF）增加。对于汞离子，检测限达到2.5×10 M，这是根据IUPAC公式C = 3σ/斜率计算得出的。Job曲线显示L与汞之间的结合化学计量比为1:1。应用Benesi-Hildebrand方程，L-Hg配合物的结合常数估计为7.54×10 M。为了验证L-Hg配合物形成过程中涉及的机制，在气相中进行了DFT和TD-DFT计算。L已被很好地用于在很宽的pH范围内识别土壤样品中的汞离子。受体L还应用于细胞成像研究。
