DNA电化学传感器在DNA片段识别与测定中的应用

Application of Electrochemical DNA Sensor in the Detection of Sequence\|Specific DNA

本文用乙基－（３－二甲基丙基）碳二亚胺盐酸盐（ＥＤＣ）和羟基丁二酰亚胺（ＮＨＳ）活化已被氧化的石墨电极，然后将单链ＤＮＡ（ｓｓＤＮＡ－１）固定在石墨电极上。运用核酸杂交技术，使具有电化学活性的染料Ｈｏｅｃｈｓｔ ３３２５８ 嵌入双链ＤＮＡ 分子（ｄｓＤＮＡ）的碱基对中，在石墨电极表面形成ｄｓＤＮＡ－Ｈｏｅｃｈｓｔ ３３２５８ 层，通过伏安法测定嵌入Ｈｏｅｃｈｓｔ ３３２５８的氧化峰电流，可以识别和测定溶液中互补的ｓｓＤＮＡ－２ 片段，ｓｓＤＮＡ－２ 的浓度在４．８×１０－ ５～１．１×１０－ ７ ｍ ｇ／ｍ Ｌ范围内，有线性关系，检测限可达６．０×１０－ ８ ｍ ｇ／ｍ Ｌ。

In this paper, the voltammetric detection of sequence\|specific DNA using Hoechst 33258 as the electroactive intercalator is reported. The anodic waves of the Hoechst\| 33258 bound to the double\|stranded DNA in cyclic voltammetry were used for the determination of complementary DNA(cDNA).The anodic currents( i \-\{pa\})of Hoechst 33258 were linearly related to the concentrations of cDNA between 4.8×10\+\{-5\} mg/mL to 1.1×10\+\{-7\} mg/mL.The detection limit was about 6.0×10\+\{-8\} mg/mL(S/N=3).