TPD修饰电化学生物传感器测定DNA片段序列

合成了一种新的吸附偶联试剂-硫酚乙酸琥珀酰亚胺酯(TPD)，将TPD吸附在金的表面，利用其琥珀酰亚胺基与客体氨基的反应，将单链DNA修饰在金电极上作为探针，以电化学方法检测能与之互补DNA样品的碱基序列和含量。杂交后的DNA采用自行合成的双[1-二茂铁按甲酰丙基-四氢化吡嗪-4-丙基氨甲酰吡啶]并吩嗪(FCZ)作指示剂进行检测，该化合物能够嵌入DNA双螺旋结构的碱基对中，显示出高度电化学活性。该传感的电流信号与DNA深度在2×10^-8～1×10^-7mol/L范围有线性关系，检测限为8×10^-10mol/L。本方法可用于检测爱滋病和乙肝病毒DNA特征序列的研究。

Sequence determination of DNA pieces using a TPD modified electrochemical biosensor

A new modifier N-[6-(thien-3-yl)acetoxy]-pyrrolidine- 2,5-dione(TPD) and a sensitive electroactive indicator di[1-(ferrocene- carbamoylporpyl)-tetrahydropyrazine-4- (propyl carbamoyl-pyridine)-] phenazine(FCZ) have been synthesized. TPD is adsorbed on glod surface to immobilize ssDNA as probe. FCZ is intercalated in dsDNA and detected by differential pulse voltammetry. The biosensor is based on a chemically modified electrode, on which TPD-ssDNA is self- assembled. It is sensitive to cDNA with the detection limit being 8× 10^-10mol/L. The current signal of the biosensor is proportional to the concentration of cDNA in the range of 2×10^-8 to 1×10^-7mol/L. This electrochemical biosensor has been used to detect sequence- specific DNAs related to HIV-1 and HBV virus.