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为了实现对于水中铀酰离子的快速灵敏检测,本研究基于脱氧核酶(DNAzyme)对铀酰离子的高特异识别能力及荧光共振能量转移(FRET)的信号产生原理,建立了铀酰离子的荧光检测方法.结果发现,在铀酰离子存在的条件下,两端分别标记荧光基团和淬灭基团的底物链被标记淬灭基团的酶链特异性切断,释放标记荧光基团的底物链片段,使得体系的荧光信号强度得到提高.通过底物链与酶链的比例、浓度及反应时间的优化,提高了检测方法的灵敏性,结果显示,本方法对于铀酰离子的检测限可达到0.7 nmol·L~(-1)(3S/N),并在4~20 nmol·L~(-1)之间保持良好的线性检测范围,整个检测过程仅需6 min即可完成.本检测方法具有良好的选择性,常见的金属离子铜、铅、汞、砷、镁、钙等对于检测结果无明显干扰作用.对清华大学饮用水及自来水的加标回收率实验结果显示,加标回收率分别为98.0%~107.8%和90.0%~108.0%.本研究为今后铀酰离子在实际环境水体中的检测奠定了基础.
In order to achieve rapid and sensitive detection of uranyl ion in water, based on the high specific recognition ability of uranyl ion by DNAzyme and the principle of fluorescence resonance energy transfer (FRET) signal generation, the fluorescence of uranyl ion was established The results showed that in the presence of uranyl ion, the substrate chain labeled with both fluorophores and quencher groups at both ends was specifically cleaved by the enzymatic chain of the labeled quencher group, releasing the Substrate chain fragment, the fluorescent signal intensity of the system was improved.The sensitivity of the detection method was improved by the optimization of the ratio of the substrate chain to the enzyme chain, the concentration and the reaction time, and the results showed that the detection of uranyl ion by the present method The limit of detection was up to 0.7 nmol·L -1 (3S / N), and good linearity detection range was maintained between 4 and 20 nmol·L -1. The whole process could be completed in only 6 min The test method has good selectivity, common metal ions such as copper, lead, mercury, arsenic, magnesium, calcium and other test results did not interfere with the effect of Tsinghua University drinking water and tap water spiked recoveries experimental results show that, Spike recovery rates were 98.0% ~ 107.8% and 90.0% ~ 108.0%, respectively.This study laid the foundation for the future detection of uranyl ion in real environmental water.