基于功能化核酸和金纳米粒子的铀酰离子检测新方法研究

发布时间：2018-03-07 04:26

  本文选题：铀酰离子　切入点：共振光散射　出处：《南华大学》2012年硕士论文　论文类型：学位论文

【摘要】：铀是一种具有放射性的重金属，通过放射毒性与化学毒性对机体造成严重的危害，引起肾、脑等器官损伤，并造成消化、免疫、造血和生殖系统紊乱。目前存在的大多数铀检测方法操作繁琐、样本需预处理，所需仪器设备昂贵，因此，建立方便、灵敏、选择性高的铀检测新方法，对于环境中铀污染的预警、安全评价、环境治理及减少人群暴露等有着重要的现实意义。 本文第二章建立了基于未标记DNA酶-金纳米粒子系统的共振光散射法检测铀酰离子的新方法。研究表明：在pH4.5的10mmol·L~(-1)MES缓冲溶液中，铀特异性DNA酶在铀作为辅助因子的条件下发生自身断链反应，释放出ssDNA，ssDNA呈自由卷曲状态，暴露自身碱基，通过范德华力吸附在金纳米粒子上，阻止金纳米粒子在高浓度盐下聚集，使体系的共振光散射强度降低，在2.08×10~(-9)~2.00×10~(-8)mol·L~(-1)范围内，散射光强度的改变值与铀酰离子浓度呈良好线性关系，回归方程为ΔI=59.45+14761c (μmol·L~(-1))，r=0.9852，检出限为6.23×10-10mol·L~(-1)。该方法简便、快速、选择性好、灵敏度高。 本文第三章建立了基于标记DNA酶-金纳米粒子系统的共振光散射法检测铀酰离子的新方法。研究表明：延长的铀特异性DNA酶通过金硫键组装在金纳米粒子上，形成金纳米粒子复合物，在pH4.5的10mmol·L~(-1)MES缓冲溶液中，铀的浓度为1.36×10~(-8)~1.50×10~(-7)mol·L~(-1)时，，复合物在高浓度盐作用下聚集，使体系的共振光散射强度增强，回归方程为ΔI=48.83+516.24c (μmol·L~(-1))，r=0.9907，检出限为4.09×10~(-9)mol·L~(-1)。该方法选择性高、重复性好、灵敏度高。 本文第四章对铀特异性DNA酶进行改善，形成一种新的适体，在适体的基础上建立未修饰金纳米粒子的共振光散射法检测铀酰离子新方法。研究表明：DNA酶链中腺嘌呤核糖核苷酸转变成腺嘌呤脱氧核糖核苷酸仍能特异性识别UO_2~(2+)。铀浓度为2.3×10~(-8)~4.5×10~(-7)mol·L~(-1)时，共振光散射强度与铀酰离子浓度呈良好线性关系，回归方程为ΔI_(RLS)=70.88+4.100c (×10~(-8)mol·L~(-1))，r=0.9889，检出限为6.70×10~(-9)mol·L~(-1)。该方法简便、快速。
[Abstract]:Uranium is a kind of radioactive heavy metal, which causes serious damage to the body through radiotoxicity and chemical toxicity, causing damage to organs such as kidney and brain, and causing digestion and immunity. Disorders of hematopoietic and reproductive systems. Most of the existing uranium detection methods are cumbersome to operate, samples need to be pretreated, and the instruments and equipment required are expensive. Therefore, a new method for the detection of uranium, which is convenient, sensitive and selective, is established. It has important practical significance for early warning, safety assessment, environmental control and reduction of human exposure to uranium pollution in the environment. In chapter 2, a new resonance light scattering method based on unlabeled DNA enzyme gold nanoparticles system for the detection of uranyl ions has been developed. The uranium-specific DNA enzyme reacts with its own chain breaking reaction under the condition of uranium as an auxiliary factor, releasing ssDNA and ssDNA in a free curl state, exposing its own bases, and adsorbing on gold nanoparticles by van der Waals force. In order to prevent gold nanoparticles from aggregating under high concentration of salt, the intensity of resonance light scattering (RLS) of the system decreases. In the range of 2.08 脳 10 ~ (-1) ~ (-9) 脳 10 ~ (10) ~ (-8) mol 路L ~ (-1), there is a good linear relationship between the intensity of scattering light and the concentration of uranyl ion in the range of 2.00 脳 10 ~ (-8) mol 路L ~ (-1). The regression equation was 螖 I _ (鈪

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