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将鲱鱼精dsDNA通过自吸附方式固定在铅笔芯电极(CP)表面制备出DNA/CP.在pH7.38磷酸缓冲溶液(PBS)中,考察联苯胺(BZ)与铅笔芯电极表面鲱鱼精dsDNA相互作用后所导致的DNA/CP零流电位Ezcp变化.结果显示,随着BZ浓度或结合时间的增加,DNA/CP的Ezcp均正移;且当BZ浓度在8.0×10~(-7)~1.0×10~(-5) mol·L~(-1)或结合时间在2~18min内,Ezcp与BZ浓度对数lg[BZ]或结合时间呈正比关系.由此计算出dsDNA与BZ结合反应呈现一级动力学反应方程,其结合比为1∶1,表观结合常数为3.98×106L·mol~(-1),表观速率常数为2.06×104s~(-1),半衰期为3.36×10~(-5)s.本方法简单灵敏安全,对拓宽致癌或致毒小分子与DNA作用的研究方法有参考价值.
The herring sperm dsDNA was self-adsorbed on the surface of a pencil core electrode (CP) to prepare a DNA / CP. In pH7.38 phosphate buffer solution (PBS), we examined the interaction of benzidine (BZ) The results showed that Ezcp of DNA / CP was positively shifted with the increase of BZ concentration or binding time, and when the concentration of BZ was between 8.0 × 10 ~ (-7) ~ 1.0 × 10 -5 mol·L -1 or binding time within 2 ~ 18 min, Ezcp and BZ concentration logarithm lg [BZ] or binding time was proportional to calculate dsDNA and BZ binding The reaction shows a first-order kinetic equation with a binding ratio of 1: 1, an apparent binding constant of 3.98 × 106 L · mol -1, an apparent rate constant of 2.06 × 104 s -1 and a half-life of 3.36 × 10 ~ (-5) s. The method is simple and sensitive and safe, which has reference value for broadening the research methods of carcinogenesis or toxic small molecule and DNA.