适配体分子探针的信号放大新策略研究

项目名称： 适配体分子探针的信号放大新策略研究

项目编号： No.21275156

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 裴仁军

作者单位： 中国科学院苏州纳米技术与纳米仿生研究所

项目金额： 78万元

中文摘要： 面向分析化学和生物医学等领域对进一步提高靶分子检测灵敏度的重大需求，本项目研究适配体分子探针的信号放大新策略。重点研究如何将靶分子和适配体的识别转化成剪切型8-17脱氧核酶的酶放大反应信号。具体研究如下三种策略：1）用理性设计的方法构建适配体与8-17脱氧核酶的核酸嵌合体，通过适配体与靶分子的识别作用，导致嵌合体构象变化从而诱导脱氧核酶的激活；同时进行适配体调控的剪切型脱氧核酶的直接筛选，以期获得相应的对靶分子响应的嵌合体。2）级联适配体和靶分子的识别反应与8-17脱氧核酶的反应，通过识别诱导解离释放短链DNA片段，此片段进而激活下游的处于失活状态的8-17脱氧核酶。3）建立上游和下游剪切型脱氧核酶的双酶反应的级联系统，通过双酶的双重放大作用，来显著提高对靶分子的检测灵敏度。并对如何提高信号放大系统对靶分子识别的选择性进行研究。进而探讨这三种分子探针信号放大策略的构建规律和内在机理。

中文关键词： 适配体；脱氧核酶；分子探针；信号放大；生物传感器

英文摘要： Aptamers are single-stranded DNA or RNA molecules and selected from random oligonucleotide pools by a process called Systematic Evolution of Ligands by Exponential Enrichment (SELEX).The specificity and high affinity of aptamers to a wide variety of targets, coupled with the simple synthesis, thermal stability, ease of design and modification, make aptamers highly suitable for development as biomolecular probes.It is an urgent and significant task to develop highly sensitive detection methods for targets in the fields of analytical chemistry and biomedicine. For example, the early diagnosis of cancers is highly dependent on the development of a highly sensitive method for cancer biomarkers.Here, we will study the new stratgies for signal amplification of aptamer molecular probes. The specific binding properties of aptamers with their targets will be transducted to the amplified biosensing events of deoxyribozymes. Three strategies for probe signal amplification will be investigated. 1) rational design of aptazymes based on cocaine, ATP atamers and 8-17 deoxyribozyme.An aptazyme is a known aptamer sequence connected to a known deoxyribozyme sequence. In the absense of target analyte for the aptamer, the enzymatic activity can not be expressed due to inappropriate structrual folding. The presence of the target cau

英文关键词： aptamer；deoxyribozyme；molecular probe；signal amplification；biosensor