基于G-四链体-氯化血红素DNA酶比色法测定银离子和汞离子传感器的构筑

利用G-四链体DNA(5′-CTGGGAGGGAGGGAGGGA-3′)与氯化血红素结合形成G-四链体-HeminDNA酶,其能高效催化H2O2氧化反应底物由无色变为绿色,当溶液中有Ag^+或Hg^2+存在时会阻碍该DNA酶的形成,导致绿色溶液变浅。基于此,建立了比色法测定Ag^+和Hg^2+的传感器。在最佳实验条件下,溶液的吸光度与Ag^+和Hg^2+浓度分别在100.0~1000.0nmol/L和80.0~800.0nmol/L范围内具有良好的线性关系,检出限(3δ/Slope)分别为55.9nmol/L和64.3nmol/L。该方法具有较好的选择性,采用该方法对实际样品进行测试,结果满意。

Fabrication of a Sensor for Colorimetric Determination of Silver and Mercury Ions Based on G quadruplex-Hemin DNAzymes

A sensor for colorimetric determination of silver and mercury ions based on G-quadruplex-hemin DNAzymes was fabricated.The G-quadruplex-hemin DNAzymes was formed by the combination of G-quadruplex(5′-CTGGGAGGGAGGGAGGGA-3′) with hemin,which could catalyze H2O2 to oxide the substrate efficiently,and make the colorless solution become green.The presence of Ag^+ or Hg^2+ in the solution would hinder the formation of the DNAzyme,and the solution color became lighter.Under the optimal experimental conditions,there were good linear relationships for the absorbance of the solution with Ag^+ and Hg^2+ in the concentration ranges of 100.0-1 000.0 nmol/L and 80.0- 800.0 nmol/L,with detection limits(3 δ/Slope) of 55.9 nmol/L and 64.3 nmol/L,respectively.This method was of good selectivity,and was applied in the detection of real samples with satisfactory results.