目的 用电化学发光法研究含稠杂环芳烃结构的农药分子喹菌酮、噻菌灵及含稠环芳烃结构的农药甲萘威的代谢产物1,2-二羟基萘与双链DNA(ct-DNA)的相互作用。方法 将带正电荷的聚二甲基二烯丙基氯化铵(PDDA)与带负电荷的DNA层层自组装到玻碳电极(GCE)表面,构建核酸传感膜,以钌配合物二联吡啶二吡啶并[3,2-a:2′,3′-c]吩嗪钌([Ru(bpy)2dppz]2+,简称Ru-dppz)作为电化学发光指示剂,以三丙胺(TPA)作为共反应物,利用有机化合物分子与Rudppz在DNA上的竞争置换作用,测定农药分子与DNA的结合常数。结果 喹菌酮、噻菌灵和1,2-二羟基萘与DNA的结合常数分别为2.78×105、0.083 6×105、0.104×105 L/mol。用紫外-可见吸收光谱法和荧光光谱法进一步证实了其竞争置换作用。根据构效关系阐明了该作用与农药分子结构之间可能存在的内在联系。结论 电化学发光法可以快速、准确地研究喹菌酮、噻菌灵和1,2-二羟基萘与DNA的相互作用。
Objective To study the interaction of some pesticides of fused heterocyclic aromatic hydrocarbons, oxolinic aid and thiabendazole, as well as 1,2-dihydroxynaphthalene, a metabolite of pesticide carbaryl which contains fused ring aromatic hydrocarbon structure with double-stranded DNA (ct-DNA) by electrochemilumineseence (ECL) method. Methods Layer-by- layer films of positively charged polycationic (poly diallyldimethylammonium chloride) (PDDA) and negatively charged dsDNA were assembled on the surface of a glassy carbon electrode (GCE) through electrostatic adsorption to prepare DNA biosensor (DNA/PDDA/GCE). Complex of [Ru(bpy)2(dppz)]z~ (bpy = 2, 2'-bipyridine, dppz=dipyrido[3, 2-a: 2', 3'-c]phenazine) (denoted as Ru-dppz) was used as an elec~rochemiluminescence indicator in the present study.Tripropylamine (TPA) was used as an electron donor to chemically amplify the signal intensity of electrochemiluminescence of the indicator.The binding constants of pesticides and metabolite with DNA were investigated according to the competitive displacement effect of the organic compound molecule and Ru-dppz at DNA. Results The binding constants of oxolinic aid, thiabendazole and 1, 2-dihydroxynaphthalene with DNA were 2.78x105 L/mol, 0.083 6x10s L/mol and 0.104x105 L/mol, respectively. Ultraviolet-visible spectroscopy and fluorescence spectroscopy were used to confirm the competitive displacement effect. The differences of the binding constants resulted from the different molecular structure of the compounds. Conclusion Electrochemiluminescence (ECL) method is applicable to the study of the interaction of oxolinic aid, thiabendazole and 1, 2-dihydroxynaphthalene with DNA.