A new organic molecule probe has been introduced as a “turn-off” fluorescent sensor to detect trace quantities of UO 2 2+ in the presence of several transition metals with promising results. The procedure is based on quenching the fluorescence intensity of 6-chloro-2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide ( L ) in the presence of various UO 2 2+ concentrations in methanol. The UO 2 2+ and L species interact through electrostatic interaction between negatively charged nitrogen atom of the sulfonamide group of L and positively charged UO 2 2+ , thus facilitating the non-radiative recombination of UO 2 2+ and L through the charge transfer or electron transfer processes and leading to the fluorescence quenching of L . The mechanism of quenching was addressed and proved to be static quenching. The impressive quenching of the fluorescence intensity of L by different concentrations of UO 2 2+ has been successfully used as a new sensor to measure UO 2 2+ in methanol at λ ex = 340 nm, λ em = 380 nm with a linear dynamic range of 0.08–5.0 µM and detection limit and quantification limit of 0.0276 and 0.0837 µM, respectively. The L sensor shows interesting advantages compared to other developed sensors with adequate performance, such as broader linear range and lower detection limit, selectivity, and simplicity, which illustrate its useful practical use. Graphical abstract Fluorescence quenching detection of UO 2 2+ in aqueous solution based on an organic molecule probe of 6-chloro-2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide.

中文翻译：

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基于6-氯-2H-1,2,4-苯并噻二嗪-7-磺酰胺1,1-二氧化物的有机分子探针对水溶液中UO22 +的荧光猝灭检测

引入了一种新型有机分子探针作为“关断”荧光传感器，可在多种过渡金属存在下检测痕量的UO 2 2+，并获得可喜的结果。该程序基于在甲醇中存在各种UO 2 2+浓度的条件下淬灭6-氯-2 H -1,2,4-苯并噻二嗪-7-磺酰胺1,1-二氧化物（L）的荧光强度。UO 2 2+和L物种通过L的磺酰胺基团的带负电荷的氮原子与带正电荷的UO 2 2+之间的静电相互作用而相互作用，从而促进UO 2 2+和L通过电荷转移或L的非辐射重组。电子转移过程并导致L的荧光猝灭。解决了淬灭机理，并证明是静态淬灭。不同浓度的UO 2 2+对L的荧光强度产生的令人印象深刻的猝灭作用已成功地用作一种新的传感器，用于在λex = 340 nm，λem = 380 nm处以线性动态范围测量甲醇中的UO 2 2+ 0.08–5.0 µM的检出限和0.0276和0.0837 µM的检出限。与其他开发的具有足够性能的传感器相比，L传感器显示出有趣的优势，例如更宽的线性范围和更低的检测限，选择性和简便性，这说明了其实用的实用性。图形摘要基于6-氯-2 H -1,2,4-苯并噻二嗪-7-磺酰胺1,1-二氧化物的有机分子探针，对水溶液中的UO 2 2+进行了荧光猝灭检测。