【作者】 万莹； 宋世平； 樊春海；

【Author】 WAN Ying,SONG Shi-ping~* and FAN Chun-hai(Shanghai Institute of Applied Physics,Chinese Academy of Sciences, Shanghai 201800)

【机构】 中国科学院上海应用物理研究所；

【摘要】 报道了一种新型的夹心法检测可卡因电化学传感器。该传感器基于可卡因的核酸适体与其特异性结合的性质。可卡因的适体被巧妙地切割成两段寡核苷酸序列,并将其中一段末段修饰巯基通过金硫键组装在金电极表面,而另一段末段修饰荧光素。当可卡因存在时,这两段序列与可卡因特异性结合形成夹心结构,然后再加入抗荧光素标记的辣根过氧化物酶与荧光素特异结合,通过检测辣根过氧化物酶催化底物产生的氧化还原电流进行信号检测。通过该策略,我们对可卡因的检测限可达到10μmol/L以下。更多还原

【Abstract】 In this work,we report a novel sandwich type of electrochemical biosensor for cocaine detection.In this design, the cocaine aptamer is engineered to be two pieces of random,coil-like single-stranded DNA,which reassembles into the intact aptamer tertiary structure in the presence of the specific target.While one strand was labeled with biotin which could be immobilized on the gold electrode and the other strand was labeled with FITC,the aptamer tertiary structure was formed at the electrode and antiFITC-HRP was added.We then electrochemically interrogated the electrical current for peroxidase-catalyzed hydrogen peroxide.The detection limit of this biosensor was less than 10μmol/L.更多还原