Designing a colorimetric sensor containing nitrogen and oxygen atoms for uranyl ions identification: Chromatic mechanism, binding feature and on-site application
Designing a colorimetric sensor containing nitrogen and oxygen atoms for uranyl ions identification: Chromatic mechanism, binding feature and on-site application
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DOI：
10.1016/j.snb.2020.127681
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发表时间：
2020-03
影响因子：
8.4
通讯作者：
Xumeng Wu;Yu Mao;Dongyuan Wang;Qiuxiang Huang;Q. Yin;Ming Zheng;Qinghua Hu;Hongqing Wang
中科院分区：
文献类型：
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作者：
Xumeng Wu;Yu Mao;Dongyuan Wang;Qiuxiang Huang;Q. Yin;Ming Zheng;Qinghua Hu;Hongqing Wang
在设计比色铀酰离子传感器时，消除干扰和改善色差仍然是科学家们面临的挑战，而且也不清楚铀的种类和传感器如何协同影响不同pH下含氮或氧原子的配体的显色机制和配位模式。在此，我们设计并合成了2-(5′-(对(二苯氨基)苯基)-2′-吡啶偶氮)-5-(二乙氨基)苯酚(缩写S-LH)，用于混合溶剂中铀酰离子的比色检测。通过密度泛函理论（DFT）计算合理引入三苯胺基团，增强了S-LH对铀酰离子的色度差异，使得铀酰离子的检测限比现有的紫外可见和目视方法低约1个数量级。明确了S-LH和铀在不同pH值下的形态，很好地解释了添加铀酰离子后颜色变化不同的原因。稳定常数实验表明，S-LH在检测铀时对其他金属离子具有优异的抗干扰能力。通过HRMS、1H NMR滴定和DFT计算进一步证实了S-LH对UO22+的配位结构。最后，制备了S-LHa比色试纸条，用于湘江铀酰离子的检测，为环境中铀酰离子的现场实时检测提供了方法。
It is still a challenge for scientists to eliminate interference and improve chromatic aberration in designing colorimetric uranyl ions sensors, and it is also not clear how the species of uranium and sensor synergistically affect the coloration mechanism and coordination mode of ligands containing nitrogen or oxygen atoms at different pH. Herein, we design and synthesize 2-(5′-(p-(diphenylamino)phenyl)-2′-pyridylazo)-5-(diethylamino)phenol (abbr.S-LH) for the colorimetric detection of uranyl ions in mixed solvents. The rational introduced triphenylamine group by density functional theory (DFT) calculation enhances the chromaticity difference of theS-LHtoward uranyl ions, making the detection limits of the uranyl ions approximately one order of magnitude lower than that of the present UV–vis and visual method. The species ofS-LHand uranium at different pH are clarified and it well explains the reason of different color changes after adding uranyl ions. Stability constant experiments show thatS-LHhas excellent anti-interference to other metal ions during detecting uranium. The coordination structure ofS-LHtowards UO22+is further confirmed by HRMS,1H NMR titration, and DFT calculation. Finally, colorimetric test strips withS-LHare prepared to detect uranium in Xiang River, providing an on-site and real-time method to detect uranyl ions in the environment.