新型无标记核酸适体生物传感器的开发与应用

项目名称： 新型无标记核酸适体生物传感器的开发与应用

项目编号： No.20805002

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 生物科学

项目作者： 周颖琳

作者单位： 北京大学

项目金额： 25万元

中文摘要： 核酸适体是与靶分子具有高特异性、高亲和力结合的寡聚核苷酸链，其特性在很多方面优于抗体。将核酸适体作为生物传感器的识别元件用于各类目标分子的检测是近年来生化分析的研究热点。但目前为止这类生物传感器大多数都是将荧光分子或电活性分子标记到核酸适体上，借助核酸适体与靶分子作用前后构象等的变化所导致的信号的改变来作为传感信号用于生物大分子的检测。本课题进行无标记核酸适体生物传感器的开发与应用，以场效应材料(半导体-绝缘层)和金电极作为基底材料，通过对基底材料的选择和优化以及核酸适体固定化方法的研究，将核酸适体有效连接到基底材料表面。借助核酸适体与靶分子作用前后对基底材料表面电荷分布的影响所导致的传感信号的变化（如电化学阻抗的变化）直接用于靶分子的检测，构建了不同类型的无标记核酸适体传感器，实现了对大分子蛋白质和小分子的灵敏检测。这些研究工作将进一步促进电化学核酸适体传感器的发展和应用。

中文关键词： 核酸适体；靶分子；无标记核酸适体传感器；固定化；相互作用

英文摘要： Aptamers are a new class of synthetic oligonucleotides which can recognize their targets with high affinity and specificity，often superior to those of antibodies. Thus aptamers are recently becoming promising recognition probes of biosensor for the detection of different kinds of targets. Until to now, most of aptamer-based sensors (aptasensor)are based on the detection of optical or electrochemical signal changes, caused by binding-induced conformational changes of aptamers which are labelled with fluorescent probe or electrochemical probe. Our project is to develop non-labelled aptasensor. Using field-effect structure (semiconductor-insulator) or gold electrode as substrates, our investigation will be focused on the selection and optimization of substrates and the immolization of aptamers on the substrates. Different kinds of aptasensors have been developed for sensitively detecting large molecules such as proteins and small molecules through the change of the transducer signal such as electrochemical impedance spectroscopy （EIS） caused by the surface charge distribution of the substrates which is influenced by the interaction between aptamer and target. All research work will boost the further development and application of electrochemical aptasensor.

英文关键词： Aptamer; target; non-labelled aptasensor; immobilization；interaction