【摘要】 目的应用核酸适体133DNA和N-甲基中卟啉IX（NMM）,建立铅离子和放射性惰性气体氡的非标记荧光传感分析新方法。方法以核酸适体133DNA为识别探针,以N-甲基中卟啉IX（NMM）为荧光信使,采集氡辐射稳定的子体铅;用Pb²⁺离子诱导单链133DNA发生构象转变,形成稳定的G-四链体。G-四链体与NMM键合,导致体系荧光信号敏锐变化,灵敏检测铅和氡。结果 Pb²⁺离子浓度c_Pb为5.0 nmol/L⁹0 nmol/L时,荧光强度改变量（ΔF）与Pb²⁺离子浓度之间呈现良好的线性关系,ΔF=1.80c_Pb（nmol/L）-2.07,r=0.990 9;氡累积浓度c_Rn为2.0×10⁴Bq·h/m³¹2.0×10⁴Bq·h/m³时,ΔF值与氡累积浓度之间的数学定量模型为ΔF=7.71c_Rn+3.00,r=0.996 5。新方法对铅的检出限为1.67 nmol/L,对氡的检出限为1.19×10³Bq·h/m³,低于中国国家标准方法中氡的累积测量的检出限（2.1×10³Bq·h/m³）。结论本方法可以灵敏检测铅和氡,K⁺离子等干扰小。在氡的采样和检测过程中,避免了辐射危害;氡样品可直接测定,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核酸适体荧光传感检测新领域。更多还原

【Abstract】 Objective To establish a method for the determination of lead ion and radioactive inert gas radon by using the aptamer 133 DNA and N-methyl porphyrin IX（ NMM）. Methods Using the aptamer 133 DNA as a probe and N-methylmesoporphyrin IX（ NMM） as a fluorescent dye,daughter lead with stable radon decay was collected. Pb²⁺induced 133 DNA for construction changes to form a stable G-quadruplex. The interaction between G-quadruplex and NMM resulted in a sharp fluorescence signal change. The lead ion and radon were detected. Results Good linearity between fluorescence intensity change（ ΔF） and Pb²⁺concentrations was obtained when the concentrations of Pb²⁺( c_Pb) within 5. 0 nmol/L-90 nmol/L,ΔF = 1. 80c_Pb（ nmol/L）-2. 07,r = 0. 990 9; when the concentration of radon was within 2. 0 ×10⁴Bq·h/m³-12. 0 ×10⁴Bq·h/m³,ΔF = 7. 71c_Rn+ 3. 00,r = 0. 996 5. The detection limit of the new method was 1. 67 nmol/L and and the detection rate of radon was 1. 19 ×10³Bq·h/m³,respectively. This method was far below the detection limit for cumulative radon from the Chinese national standard method（ 2. 1 ×10³Bq·h/m³）. Conclusion The method can be sensitive to detect lead and radon,K⁺ions and so on. In the process of sampling and testing,radiation hazard is avoided; radon samples can be directly measured with simple operation and low cost,which expands a new fluorescence sensing detection field of aptamers for radioactive substances and gases.更多还原