中文摘要：

目的建立快速、灵敏检测四氯对苯醌（TCBQ）对DNA损伤的电化学发光法（ECL）。方法将带正电荷的聚二甲基二烯丙基氯化铵（PDDA）和带负电荷的小牛胸腺双链DNA（ds—DNA）层层自组装在玻碳电极（GCE）表面，制成DNA传感器，采用具有灵敏电化学发光特性的金属配合物二联吡啶二毗啶并[3，2-a：2’，3’-c]吩嗪钌（[Ru（bpy）：（dppz）]2＋，简称为Ru—dppz）作为DNA探针分子。当DNA受损伤后，嵌入双链DNA膜中的Ru—dppz减少，ECL信号减弱，由此可以检测DNA受损程度。结果未受损受的DNA具有完整的双螺旋结构，可以产生非常强的ECL信号。DDA／DNA修饰膜在100μmol／LTCBQ溶液或100μmol／LTCBQ-2．0mmol／L H2O2溶液中温育一段时间后，ECL信号明显减弱。结论该方法能快速、灵敏检测由TCBQ单独与DNA形成共价键所造成的DNA损伤，及TCBQ与H2O2反应生成的羟基自由基（·OH）对DNA造成的氧化性损伤。

英文摘要：

Objective To develop a new electrochemiluminescent method in order to sensitively and rapidly detect DNA damage induced by tetraehloro-1, 4-benzoquinone （TCBQ）. Methods DNA modified films were constructed by layer-by-layer adsorption of polycationic poly（diallyldimethylammonium chloride） （PDDA） and negatively charged double-stranded DNA on the surface of a glassy carbon electrode （GCE） to prepare a DNA sensor. A DNA intercalator, [Ru（bpy）2（dppz）]2＋ （denoted hereafter as Ru-dppz, bpy： 2, 2＇-bipyridine, dppz：dipyrido[3, 2-a： 2＇, 3＇-c]phenazine）, was employed as a sensitive electrochemilumineseence （ECL） probe. After DNA is damaged the amount of Ru-dppz intercalated in DNA film should be decreased to cause the decrease of ECL signal. Results Undamaged DNA with intact double helix structure produced a strong ECL signal. However, after the sensor was incubated in 100 μmol/L TCBQ or a mixed solution of 100 μmol/L TCBQ and 2.0 mmol/L H2O2, ECL signal decreased significantly. Conclusion The ECL method developed in this paper can be applied to rapidly and sensitively detect DNA damage, including DNA adduct formation in the presence of TCBQ alone due to TCBQ covalently bound with DNA, and oxidative DNA damage induced by hydroxyl radical （·OH） generated from reaction between TCBQ and H2O2.