Roja Somi Santharam, Sneha Sunil P, Darussalam Muhammad Maqsood, Manoharan Vidhyashree, Prakash John, Ranjith Kumar Raju
Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625021 Tamil Nadu, India.
Department of Chemistry, School of Basic and Applied Sciences, Central University of Tamil Nadu, Thiruvarur 610005 Tamil Nadu, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 May 15;333:125853. doi: 10.1016/j.saa.2025.125853. Epub 2025 Feb 5.
Copper (Cu) is essential for biological systems and animal-plant tissues, but Cu ions are also significant environmental pollutants. An imbalance in non-toxic Cu levels can lead to health issues. This study focuses on the development of a novel fluorescent turn-on probe, 3,4-dihydrobenzo[4,5]imidazole[2,1-b]quinazoline-1(2H)-one (HBQ) for the selective and sensitive detection of Cu ions. The synthesis of HBQ was achieved from the reaction of 2-((dimethylamino)methylene)-cyclohexane-1,3-dione and 2-aminobenzimidazole. The photophysical properties of HBQ were investigated in various solvents. The strong binding of HBQ to Cu causes a blue shift in the emission maxima and enhanced fluorescence due to reduced non-radiative decay, highlighting its selectivity for Cu detection. Absorption and emission spectroscopy revealed the binding interactions, sensitivity, and selectivity of HBQ toward Cu ions. The turn-on fluorescence of HBQ shows high sensitivity, with detection (LOD) and quantification (LOQ) limits extending to sub-micron concentrations. The sensor's reliability and applicability were further validated using real samples, with a recovery rate of approximately 100 ± 2 %.
铜（Cu）对生物系统和动植物组织至关重要，但铜离子也是重要的环境污染物。无毒铜水平的失衡会导致健康问题。本研究重点在于开发一种新型荧光开启探针，即3,4-二氢苯并[4,5]咪唑并[2,1-b]喹唑啉-1（2H）-酮（HBQ），用于选择性和灵敏地检测铜离子。HBQ是由2-（（二甲氨基）亚甲基）-环己烷-1,3-二酮与2-氨基苯并咪唑反应合成的。在各种溶剂中研究了HBQ的光物理性质。HBQ与铜的强结合导致发射最大值发生蓝移，并且由于非辐射衰变减少而增强了荧光，突出了其对铜检测的选择性。吸收光谱和发射光谱揭示了HBQ与铜离子的结合相互作用、灵敏度和选择性。HBQ的开启荧光显示出高灵敏度，检测限（LOD）和定量限（LOQ）延伸至亚微米浓度。使用实际样品进一步验证了该传感器的可靠性和适用性，回收率约为100±2%。
