基于分子信标及核酸染料SYBR Green Ⅰ定量检测土壤中的汞

利用分子信标、单链核酸（ss DNA）及核酸染料SYBR GreenⅠ,通过同步荧光分析法,建立了一种高灵敏、高选择性土壤汞（Hg2＋）的定量检测方法。在该体系中,分子信标的荧光基团设计为荧光胺（FAM）,分子信标的环设计为与ss DNA互补,但有4个T碱基错配的序列。在Hg2＋存在时,分子信标的环与ss DNA通过＂T-Hg2＋-T＂特异性结合形成双链DNA,分子信标的茎被打开,荧光基团与猝灭基团分开,荧光恢复;同时,核酸染料SYBR GreenⅠ与双链DNA作用,SYBR GreenⅠ的荧光信号显著增强。SYBR GreenⅠ与FAM的最大激发波长与最大发射波长都很接近,通过同步荧光分析法...

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Bibliographic Details
Published in分析化学 Vol. 43; no. 8; pp. 1125 - 1129
Main Author 翟琨 向东山 朱俊 胡红青
Format Journal Article
LanguageChinese
Published 湖北民族学院化学与环境工程学院,恩施445000%湖北民族学院化学与环境工程学院,恩施,445000%华中农业大学资源与环境学院,武汉,430070 2015
华中农业大学资源与环境学院,武汉430070
Subjects
Green
分子信标
土壤
定量检测
核酸染料SYBR
汞
定量检测
Nucleic acid dye SYBR Green
Soil
Molecular beacon
分子信标
Mercury
汞
Quantitative detection
核酸染料SYBR Green
土壤
Online AccessGet full text
ISSN0253-3820
DOI10.11895/j.issn.0253-3820.150122

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Summary:利用分子信标、单链核酸（ss DNA）及核酸染料SYBR GreenⅠ,通过同步荧光分析法,建立了一种高灵敏、高选择性土壤汞（Hg2＋）的定量检测方法。在该体系中,分子信标的荧光基团设计为荧光胺（FAM）,分子信标的环设计为与ss DNA互补,但有4个T碱基错配的序列。在Hg2＋存在时,分子信标的环与ss DNA通过＂T-Hg2＋-T＂特异性结合形成双链DNA,分子信标的茎被打开,荧光基团与猝灭基团分开,荧光恢复;同时,核酸染料SYBR GreenⅠ与双链DNA作用,SYBR GreenⅠ的荧光信号显著增强。SYBR GreenⅠ与FAM的最大激发波长与最大发射波长都很接近,通过同步荧光分析法检测时,两种荧光染料的荧光峰重叠,荧光信号增强,可实现Hg2＋的高灵敏检测。体系的最优检测条件为：缓冲溶液的p H=8.0,孵育温度为50℃,孵育4 min,缓冲溶液中Na Cl的浓度为30 mmol/L,SYBR Green I工作液的体积为100 0L。在优化条件下,Hg2＋浓度在5×10 10~4.0×10 8mol/L时,SYBR GreenⅠ及FAM总的荧光强度（ΔI,为体系在存在和不存在Hg2＋时的荧光强度之差）与Hg2＋浓度（C）间有良好的线性关系,其拟合的回归方程为ΔI=1.3949C＋19.3596（R2=0.9976）,方法检出限（3σ）为3×10 10mol/L。本方法操作简单、快速、选择性好、灵敏度高、重复性好。
Bibliography:22-1125/O6
ZHAI Kun, XIANG Dong-Shan, ZHU Jun, HU Hong-Qing 1 （ College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China） 2 （ School of Chemical and Environmental Engineering, Hubei University for Nationalities, Enshi 445000, China）
Mercury; Molecular beacon; Nucleic acid dye SYBR Green I; Quantitative detection; Soil
A highly sensitive and selective fluorescence method for quantitative detection of mercury in soil was developed based on molecular beacon （ MB）, single-stranded nucleic acid （ssDNA） and nucleic acid dye SYBR Green I by synchronous fluorescence analysis. In this strategy, the fluorophore of MB was 6-carboxyfluorescein group （ FAM）, and the loop of MB was complementary to the ssDNA with four T-T mismatches. In the presence of Hg2＋, the MBs and ssDNA with T-T mismatches formed double-stranded DNA （dsDNA） via T-Hg2＋-T coordination structure, then the fluorophore FAM was separated from the quencher BHQ-1, thus emitted fluorescence. Meanwhile, SYBR Green I bound to dsD
ISSN:0253-3820
DOI:10.11895/j.issn.0253-3820.150122