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目的应用核酸适体9-3-35和硫黄素T,建立放射性惰性气体氡的非标记荧光传感分析新方法。方法用硫磺素T诱导富G序列核酸适配体9-3-35形成稳定的G-四链体结构,产生荧光信号,采集氡辐射得到稳定的子体铅,加入Pb~(2+)后导致体系荧光信号敏锐变化,灵敏检测氡。结果 Pb~(2+)离子浓度为1.0 nmol/L~125.0 nmol/L时,荧光强度改变量(ΔF)与Pb~(2+)离子浓度呈现良好的线性关系,ΔF=9.13cPb+163.40,r=0.995 3;氡累积浓度为3.0×104Bq·h/m~3~2.2×105Bq·h/m~3时,ΔF值与氡累积浓度之间的数学定量模型为ΔF=35.59cRn+229.51,r=0.994 0。新方法对铅的检出限为0.312 nmol/L,对氡的检出限为1.87×103Bq·h/m~3,低于国家标准方法中氡的累积测量的检出限(2.1×103Bq·h/m~3)。结论本方法可以灵敏检测氡,在氡的采样和检测过程中避免了辐射危害;可直接测定氡样品,操作简单,成本低廉,拓展了核酸适体对放射性物质和气体的荧光传感检测新领域。
Objective To develop a new method for non-labeled fluorescence sensing analysis of radon, a radioactive noble gas, using aptamer 9-3-35 and thioflavin T. Methods Thioflavin T induced G-rich aptamer 9-3-35 to form a stable G-quadruplex structure and generate fluorescence signals. Radionuclides were collected to obtain a stable progenitor Pb. After addition of Pb 2+ Resulting in a sharp change in fluorescence signal system, sensitive detection of radon. Results When the concentration of Pb ~ (2+) was 1.0 nmol / L ~ 125.0 nmol / L, the change of fluorescence intensity (ΔF) showed a good linear relationship with the concentration of Pb 2+ ion, ΔF = 9.13cPb + 163.40, r = 0.995 3, and the radon concentration is 3.0 × 104Bq · h / m ~ 3 ~ 2.2 × 105Bq · h / m ~ 3, the mathematical quantitative model between ΔF and cumulative concentration of radon is ΔF = 35.59cRn + 229.51, r = 0.994 0. The detection limit of new method for lead was 0.312 nmol / L and the detection limit of radon was 1.87 × 103Bq · h / m ~ 3, which was lower than the detection limit of cumulative measurement of radon in national standard method (2.1 × 103Bq · h / m ~ 3). Conclusion The method can detect radon sensitively and avoid the radiation hazard during the sampling and testing of radon. The method can directly measure radon samples with simple operation and low cost, and expands the new field of aptamer detection of radioactive substances and gases by fluorescence .