中文摘要：

该文报道了一种基于酶级联扩增的电化学核酸适体检测腺苷的新方法。当腺苷存在时．滚环扩增的引物通过E．coliDNA连接酶的作用与通过巯基组装在金电极上的固定探针连接。在pHi29DNA聚合酶的作用下，滚环扩增反应进行并产生一条与环形探针完全互补的长的单链．然后将大量金纳米粒子标记的核酸探针与滚环扩增的产物杂交。该传感界面电化学行为的结果表明，通过酶级联扩增的方法提高了检测腺苷的阻抗响应灵敏度，且选择性和重现性良好。用于腺苷的检测时，其线性范围为2．0μmol／L～100μmol／L，最低检测浓度为2．0μmol／L，表明该传感界面的设计可作为一种通用方法而有望用于其它目标物的检测。

英文摘要：

A novel electrochemical aptamer sensing interface based on enzyme cascade amplification has been designed and constructed for detection of adenosine in this paper. In the presence of adenosine, the primer of the rolling circle amplification （RCA） was linked with the thiol-immobilized probe modified on gold electrode by E.coli DNA Ligase. The RCA was performed with pHi29 DNA polymerasc to produce a long single strand, which was complementary to the circle template probe. Large amounts of gold nanoparticles labeled oligonucleotide probes were hybridized with the product of RCA. As a result, the impedance response of the sensing interface for recognition of adenosine was enhanced by the enzyme cascade amplification strategy. The proposed sensor possessed nice selectivity and reproducibility, and was applied to determination of adenosine samples with a linear range between 2.0μ mol/L and 100 μmol/L and a detection limit of 2.0 μmol/L. It can be seen that the strategy for design of the proposed sensing interface is expected to be used for any other targets detection as a general method.