基于双发射Ln-MOFs的比率荧光传感器检测UO22+  

A Ratiometric Fluorescent Sensor for UO22+Detection Based on Dual-emission Ln-MOFs

作　　者：彭洪波 李世琪 曹小红[1,2] 刘云海[1,3] PENG Hong-bo;LI Shi-qi;CAO Xiao-hong;LIU Yun-hai(Jiangxi Province Key Laboratory of Functional Organic Polymers,East China University of Technology,Nanchang 330013,China;School of Chemistry and Material,East China University of Technology,Nanchang 330013,China;School of Applied Engineering,Gandong University,Fuzhou 344000,China)

机构地区：[1]东华理工大学功能有机高分子江西省重点实验室,江西南昌330013 [2]东华理工大学化学与材料学院,江西南昌330013 [3]赣东学院应用工程学院,江西抚州344000

出　　处：《分析测试学报》2024年第10期1626-1634,共9页Journal of Instrumental Analysis

基　　金：国家自然科学基金项目(22166005)。

摘　　要：铀作为一种放射性元素,在水体中具有高流动性以及对生物体的高毒性,开发一种能够快速、灵敏检测水体中痕量UO_(2)^(2+)的分析方法显得极其重要。该研究采用双金属策略成功制备具有双发射中心的Eu/ZrUiO-66-NH_(2),并以此构建比率荧光传感器实现了对UO_(2)^(2+)的可视化检测。以Eu^(3+)为第二金属源部分取代Zr4+,有机配体通过“天线效应”敏化Eu^(3+)的禁阻跃迁,可使Eu/Zr-UiO-66-NH_(2)呈现双发射中心。同时,因Eu^(3+)和Zr4+的竞争配位而产生的晶格缺陷增大了MOFs的孔径尺寸,有利于UO_(2)^(2+)在孔道内的富集,进一步提高荧光传感的灵敏度。采用扫描电子显微镜、X射线粉末衍射仪、N2吸脱附曲线和荧光光谱等对Eu/Zr-UiO-66-NH_(2)的缺陷结构和光学性能进行表征,并考察了Eu^(3+)的掺入量、溶剂、荧光探针用量、时间等因素对传感器检测效果的影响。在99%乙醇-水溶液中预先富集30 min,加入UO_(2)^(2+)后,Eu/Zr-UiO-66-NH_(2)发生明显的荧光增强,IF450/IF620与UO_(2)^(2+)浓度在100~900 nmol/L范围内呈现出良好的线性关系,检出限为16.1 nmol/L。紫红色到蓝色的荧光色调转变更有利于现场半定量检测,20倍浓度的各种干扰离子不会影响Eu/Zr-UiO-66-NH_(2)对UO_(2)^(2+)的荧光响应。紫外-可见吸收光谱、X射线光电子能谱等实验证明Eu/Zr-UiO-66-NH_(2)的荧光增强为动态的电子转移过程。该传感器成功应用于自来水样品中UO_(2)^(2+)含量的测定,具有良好的应用前景。Uranium,as a radioactive element,has high mobility in water and high toxicity to organ⁃isms.Therefore,it is extremely important to develop an analytical method that can quickly and sensi⁃tively detect trace amounts of UO_(2)^(2+)in water.In this study,dual-emission Ln-MOFs(Eu/Zr-UiO-66-NH_(2))were successfully prepared by using bimetallic strategy,and the ratiometric fluorescent sen⁃sor was constructed to realize the visual detection of UO_(2)^(2+).By partially replacing Zr4+with Eu^(3+)as the second metal source,the organic ligand sensitizes the forbidden transition of Eu^(3+)through the“an⁃tenna effect”,and the Eu/Zr-UiO-66-NH_(2) exhibits double emission centers.Moreover,the lattice defects generated by the competitive coordination of Eu^(3+)and Zr4+increase the pore size of MOFs,which is conducive to the enrichment of UO_(2)^(2+)in the pore channel and further improves the sensitivity of fluorescence sensing.Scanning electron microscopy(SEM),X-ray powder diffractometer(XRD),N2 adsorption-desorption experiment and fluorescence spectroscopy were used to characterize the de⁃fect structure and optical properties of Eu/Zr-UiO-66-NH_(2),and the effects of the doping amount of Eu^(3+),solvent,fluorescent probe dosage and time on the detection of the sensor were investigated.Following the enrichment of UO_(2)^(2+)in a 99%ethanol solution for a period of 30 min,the Eu/Zr-UiO-66-NH_(2) exhibited a notable enhancement in fluorescence intensity.The IF450/IF620 exhibited a good lin⁃ear relationship with the concentration of UO_(2)^(2+)within the range of 100-900 nmol/L,and the detec⁃tion limit was 16.1 nmol/L.The shift in fluorescence hue from violet to blue was more conducive to on-site semi-quantitative detection.The 20-fold concentration of various interfering ions did not affect the fluorescence response of Eu/Zr-UiO-66-NH_(2) to UO_(2)^(2+).The results of UV-Vis spectroscopy and X-ray photoelectron spectroscopy(XPS)indicated that the fluorescence enhancement process was a dynamic electron transfer m

关 键 词：双金属策略 Ln-MOFs 比率荧光传感器 铀酰 

分 类 号：O657.3[理学—分析化学] O614.62[理学—化学]