氟罗沙星-铜络合物与DNA的电化学研究

采用单扫描法和循环伏安法研究了氟罗沙星-铜-DNA三元体系的电化学行为,建立了利用电活性物质氟罗沙星-铜测定DNA的新方法。在0 05mol/L、pH=7 12的KH2PO4-NaOH缓冲溶液中,氟罗沙星-铜络合物在-0 36V(vs.SCE)处产生一个不可逆的并具有吸附性质的还原峰,DNA的加入使其峰电流降低,但峰电位不变。在最佳实验条件下,峰电流的差值(Δip)与DNA的浓度成正比,小牛胸腺DNA的线性范围为5 0×10-7～2 0×10-5g/mL,检出限为8 0×10-8g/mL。采用本方法测定了合成样品中DNA的含量,结果满意。

Eletrochemicai Study of the Fleroxacin-Cu (Ⅱ) System with DNA

The electrochemical behavior of ternary system of FLRX-Cu(Ⅱ)-DNA was studied by linear sweep voltammetry and cyclic voltammetry. A new method for the quantitation of DNA was developed by the votammetric study of electrochemically active complexes of FLRX-Cu(Ⅱ). In the 0.05mol/L pH=7.12 KH_(2)PO_(4)-NaOH buffer, a well-defined irreversible and adsorptional reduction peak of FLRX-Cu(Ⅱ) was obtained at E_(p)= -0.36V (vs.SCE).In the presence of DNA, the formation of the electrochemically non-active complexes resulted in the decrease of its peak current. Under the optimum conditions, the decrease of the peak current (Δi_(p)) was proportional to the concentration of DNA. The linear range was 5.0×10~(-7)～2.0×10~(-5)g/mL and the detection limits was 8.0×10~(-8)g/mL for calf thymus DNA. This method exhibits good recovery and high sensitivity.