核酸荧光探针检测铅离子的研究

Study on Nucleic Acid Fluorescent Probe Detection of Lead Ion

将8-17 DNAzym e增加2个＂G-C＂碱基对进行增强热稳定性的结构修饰,并标记上1个荧光基团＂FAM＂和2个荧光猝灭基团＂Dabcyl＂,设计成双猝灭Pb2＋荧光探针。研究了该探针对Cd2＋、Zn2＋、Mg2＋、Cu2＋、Mn2＋、Pb2＋6种二价金属离子的响应,结果表明探针对Pb2＋具有很强的特异性,在探针浓度为2.5×10-7mol/L时,Pb2＋浓度在8.5×10-8~7.5×10-6mol/L范围内和探针的荧光强度呈线性关系,检出限为8.5×10-8mol/L。该探针可用于Pb2＋的定性和定量检测。

Structure of 8-17 DNAzyme was modified with two pairs of ＂G-C＂to enhance its secondary structure thermal stability and a double quenching fluorescent probe was designed by employing one fluorophore ＂FAM＂ and two quenchers ＂Dabcyl＂ based on the fluorescence resonance energy transfer（FRET） principle.The qualitative assays was studied by monitoring the change of the probe fluorescent intensity after adding Cd2＋,Zn2＋,Mg2＋,Cu2＋,Mn2＋,Pb2＋,individually.Among these metal ions,Pb2＋ showed a strong specificity to the probe.When the probe concentration was 2.5×10-7 mol/L,a good linear relationship was found between the fluorescence intensities and Pb2＋ concentration in the range of 8.5×10-8-7.5×10-6 mol/L with a detection limit of 8.5×10-8 mol/L.The results showed that the probe could be used for both qualitative and quantitative detection of Pb2＋ at room temperature.