新型功能纳米粒子快速识别铀体系的构建及其应用研究

As the nuclear industry developed rapidly, the uranium, a toxic and weakly radioactive heavy metal element, has been excessively disposed into the environment. Human beings have a high chance of being exposed to uranium, which can cause severe adverse effects to human health. For these reasons, a highly selective and sensitive method for the detection of uranium is very important for environmental protection and human health. Nanoparticle-based colorimetric sensing assays have recently attracted considerable attention in diagnostic application due to their simplicity and versatility, which depend on the targeted analyte-induced reversible color switch between dispersion-aggregation states of chemically modified nanoparticles. In this project, we develop a more sensitive and selective but simple colorimetric platform for on-site and real-time uranyl detection utilizing chemically functionalized nanoparticles as a color indicator. Nanoparticles were first functionalized with different methods, such as interparticle crosslinking aggregation, noncrosslinking aggregation, core/shell mechanisms, etc. Some parameters affecting the determination, including the concentration, size and shape of nanoparticles and pH value have been optimized. The microstructures and physicochemical properties of functionalized nanoparticles have been characterized by Uv-Vis、SEM、EDS、HRTEM、FT-IR, etc. Then the relationship between structures and colorimetric properties has been explored. Additionally, we have tried to apply such new assays to test paper or chromogenic agent on the detection of uranyl just by the color change observed by the naked eye. The project will provide the fundamental and scientific basis for monitoring of trace uranyl in polluted natural water samples or front end effluents of nuclear power reactors, with simplicity, rapidity, low-cost, high sensitivity and selectivity.

随着核电发展，铀越来越广泛使用在核电厂与军事用途中，大规模的铀矿开采以及处理过程产生了许多废弃的残留物，对铀矿、铀矿渣堆放处、核电站及其周围空气中铀含量的快速监控对人体健康和环境保护具有极其重要的意义。纳米粒子比色测定法以纳米粒子的颜色改变充当信号报告者，目标分析物直接或间接诱发纳米粒子颜色改变实现分析检测，避免使用复杂仪器，具有方法快速、简便的优点。本项目通过对纳米粒子进行指向性功能化（非交联、交联和核-壳技术等），实现灵敏、选择性显色测定铀酰离子的目的；通过XPS、FT-IR、UV-vis和形态分析等表征手段，揭示功能化纳米粒子响应铀的作用机理，寻求微观结构与宏观性能间内在联系的规律性；通过功能化纳米粒子比色识别铀体系的建立，研制出能定性或半定量检测水体中铀的检测试纸条或显色剂，实现水源水及饮用水中铀含量的快速现场检测，核设施以及铀矿附近的环境水、铀废水的监测与预警。

以纳米金颗粒为载体，将磷酸乙醇胺修饰在其表面形成磷酸化纳米金溶液（OPA-AuNPs），实现对水溶液中UO22+的快速可视化检测。Uv-Vis、TEM、Zeta电位等方法证明了OPA-AuNPs加入UO22+的存在状态。该方法无需复杂仪器，可通过肉眼观察溶液颜色变化来判定水溶液中UO22+的存在，在最佳条件下，体系比色测定铀的肉眼识别检出限为2.09 μmol•L-1（相比废水中UO22+的浓度更低）。在最佳实验条件下，比色检测检出限为0.084 μmol•L-1（S/N=3），环境中常见离子（K+, Na+, Mn2+, Sr2+, Cs+, Hg2+, Co2+, Ni2+, Cl-, SO42-, NO2-, NO3-和 F-等）对UO22+的比色检测无干扰。该研究方向为今后废水中金属UO22+离子的即时检测，提供了一种新的途径。. 选用二乙基磷酰乙基三乙氧基硅烷（DPTS）功能化的Au@SiO2作为比色传感器，DPTS上的磷酸基团与铀酰离子螯合，诱导纳米金粒子聚集，溶液颜色发生变化，从而达到可视化检测的目的。在本实验建立的检测体系中，在最佳检测条件下：溶液pH为6.0，响应30 min时，检测效果最好，其线性方程为Y=0.0118X+0.0967，检出限为4.85×10-7 mol/L。该比色检测方法展现出良好的选择性，能够抵抗高浓度常见金属离子及稀土元素的干扰。. 自行研制了基于功能化金纳米粒子便携式现场检测铀的装置，通过该装置分别用ALD-AuNPs、2-AP-AuNPs和2-APM-AuNPs检测了铀，该装置测定铀的结果与紫外可见分光光度计分析结果基本符合。这种新装置可用于水源水、饮用水中痕量铀的现场快速检测，还可用于核设施以及铀矿附近的环境水、铀废水的监测与预警，为民众的核安全提供保障。