以孔雀石绿为探针电化学分析法测定鲱鱼精DNA

在pH 7.0的Britton-Robinson(B-R)缓冲溶液中用电化学分析方法研究了孔雀石绿(MG)与鲱鱼精ds-DNA的相互作用。循环伏安法表明,MG在-1.0~+1.5 V(vs.SCE)范围内有3个氧化还原峰。加入双链DNA后,由于MG与DNA相互作用,使MG在+0.547 V处的氧化峰电流明显降低,而峰电位基本没有改变。优化了结合反应条件,在最佳条件下,MG氧化峰电流的下降值同DNA的浓度在10.0~100.0 mg.L-1范围内呈良好线性关系,线性关系方程为Δip(μA)=0.066+0.009 6c(mg.L-1),检测限(3σ)为6.0 mg.L-1。通过DNA加入前后峰电流的变化,可计算出MG与DNA结合比n(MG)∶n(DNA)=2∶1,结合常数为5.67×108。

Electrochemical Determination of Herring Sperm DNA Using Malachite Green as Probe

The interaction of malachite green(MG) with Herring Sperm double-stranded DNA(ds-DNA) in a Britton-Robinson(B-R) buffer solution of pH=7.0 was investigated by electrochemical method.The result of cyclic voltammetry showed that malachite green had three redox peaks from-1.0 V to +1.5 V(vs.SCE).The oxidative peak current at(+0.547) V was decreased after the addition of double-stranded DNA(ds-DNA) whereas without the movement of peak potential.The decrease of the peak current was directly proportional to DNA concentration in the range of 10.0～100.0 mg·L~(-1).The regression equation was Δi_(p)(μA)=0.066+0.009 6c(mg·L~(-1)) and the detection limit was 6.0 mg·L~(-1)(3σ).It was calculated that the binding ratio of MG∶DNA was 2∶1 and the binding constant was 5.67×10~(8).