模块化DNA探针精准共组装及生物传感测量

界面探针共组装技术对电化学生物传感技术的发展非常重要，然而依赖末端化学修饰的单个DNA探针不仅增加传感器研发经济/时间成本，而且在多探针协同组装过程中，难以实现精准控制，成为电化学传感界面的技术瓶颈。本项目通过聚合腺嘌呤（PolyA）与金电极表面的强亲和力作用，研究全新的多功能DNA探针共组装技术。利用多个识别探针P模块，以及PolyA（A）组装模块，设计模块化DNA分子探针。项目成果预计实现在电化学传感界面上建立间距、比例、构型精准可控。利用该传感界面，扩展新的传感测量功能：1）通过精准控制多功能探针间距，开展生化反应动力学研究；2）基于恒定的模块比例构建自校准体系，利用探针包含的多个识别模块，开展多维度联合靶标检测；3）利用多个识别探针之间的相互作用（杂交、解链、取代等），基于空间构型的设计开展无标记实时监控生物传感策研究，为提升液体活检技术的准确度和灵敏度提供有力技术支撑。

The co-assembly of DNA-probe is widely recognized to be important for to the development of electrochemical biosensors. Unfortunately, the conventional single-strand DNA probe based on terminal chemical modification become the bottleneck of electrochemical biosensing, which not only increases the economic/time cost, but also limits the controllability in the process of co-assembly. In this project, we are going to construct a novel multi-functional DNA probe co-assembly system using the strong affinity of poly-adenine (PolyA) to the gold electrode surface. Modular DNA probes (P1-An-P2)n will be designed containing multiple recognition probes (Capture probe, P-module) and assembly modules (PolyA, A-module). As a result of our project, an electrochemical biosensing interface will be developed, with highly improved controllability on space distance, ratio and configuration, and innovative biosensor strategies will be developed: 1) kinetic study will be performed based on the accurately regulated distance between the multi-functional probes; 2) multi-dimensional target detection will be performed using multiple recognition modules in the probes, and more importantly, we will construct the self-calibration system based on the constant probe ratio; 3) Based on the interaction (hybridization, melting, substitution, etc.) between probes and the resulted configuration switch, we are going to develop a label-free and real-time biosensor based on the spatial configuration design.