Enhancing the response rate of strand displacement-based electrochemical aptamer sensors using bivalent binding aptamer-cDNA probes.
Enhancing the response rate of strand displacement-based electrochemical aptamer sensors using bivalent binding aptamer-cDNA probes.
复制标题
DOI：
10.1016/j.bios.2017.12.027
复制
发表时间：
2018-04
影响因子：
12.6
通讯作者：
Ziping Zhang;Cancan Tao;Jungang Yin;Yunhui Wang;Yanshen Li
中科院分区：
文献类型：
--
作者：
Ziping Zhang;Cancan Tao;Jungang Yin;Yunhui Wang;Yanshen Li
基于适体-cDNA 双链体探针（cDNA：互补 DNA）和靶标诱导链置换 (TISD) 识别的电化学适体 (EA) 传感器具有灵敏性、选择性，能够检测多种靶标分析物。虽然大量的研究工作集中在设计新的信号机制以提高传感器灵敏度上，但很少关注传感器响应率的提高。通常，之前基于 TISD 的 EA 传感器表现出相对较长的响应时间，大于 30 分钟，这主要是由于适体-cDNA 探针结构不理想，其中大多数适体碱基与 cDNA 碱基配对。为了提高此类传感器的响应率，我们在此报告了利用超分子化学中二价相互作用的概念，合理设计了快速响应且灵敏的适体-cDNA探针。我们通过连接两个短的单价 cDNA 序列设计了一条二价 cDNA 链，并将其同时与两个电极固定的适体探针杂交，形成二价结合（BB）适体-cDNA 探针。此类BB探针具有与cDNA碱基配对的适体碱基较少、响应速度快、结构稳定性好、传感器灵敏度高的优点。通过使用合理设计的BB适体-cDNA探针，成功构建了基于TISD的针对ATP的EA传感器，该传感器具有显着增强的响应率（位移平衡时间为4分钟）和高灵敏度。我们相信，我们的 BB 探针概念将有助于指导基于 TISD 的 EA 传感器的未来设计和应用。
Electrochemical aptamer (EA) sensors based on aptamer-cDNA duplex probes (cDNA: complementary DNA) and target induced strand displacement (TISD) recognition are sensitive, selective and capable of detecting a wide variety of target analytes. While substantial research efforts have focused on engineering of new signaling mechanisms for the improvement of sensor sensitivity, little attention was paid to the enhancement of sensor response rate. Typically, the previous TISD based EA sensors exhibited relatively long response times larger than 30 min, which mainly resulted from the suboptimal aptamer-cDNA probe structure in which most of aptamer bases were paired to the cDNA bases. In an effort to improve the response rate of this type of sensors, we report here the rational engineering of a quickly responsive and sensitive aptamer-cDNA probe by employing the conception of bivalent interaction in supramolecular chemistry. We design a bivalent cDNA strand through linking two short monovalent cDNA sequences, and it is simultaneously hybridized to two electrode-immobilized aptamer probes to form a bivalent binding (BB) aptamer-cDNA probe. This class of BB probe possesses the advantages of less aptamer bases paired to the cDNA bases for quick response rate and good structural stability for high sensor sensitivity. By use of the rationally designed BB aptamer-cDNA probe, a TISD based EA sensor against ATP with significantly enhanced response rate (with a displacement equilibrium time of 4 min) and high sensitivity was successfully constructed. We believe that our BB probe conception will help guide future designs and applications of TISD based EA sensors.