构建目标介导构型变化的DNA电化学传感平台用于中药重金属离子检测

Heavy metals are one of the main pollutants in Chinese herb. Reacent years, the excessive problem of heavy metals troubles the security issue of Chinese herb. Traditional detection methods for heavy metals suffers from some disadvantages,such as low precision, complicated detection procedures or high cost of the equipment, which limit its universal application in detection of heavy metal ions in Chinese herb. DNA electrochemical biosensor is a newly development integrative installation combined various technologies. It is promising to be used as a novel tool with high sensitivity, simple operation and low power consumption in the field of deavy metal detection.In this project, target-induce structure switching DNA electrochemical biosensor is planned to design as a platform for quick, sensitive and seletive dection of heavy metals in the Chinese herb medicine. Molecule beacon as well as nano material-based signal amplify strategies will be induced to improve the sensitivity of the designed biosensor. Electrochemical technology, surface morphology analysis (such as Atomic force microscope, scanning electron microscopy,ect.)will be used to characterize the properties of the biosensor. This project aim at make a major breakthrough in the heavy metal detection technology for traditional Chinese medicine. These sensing platforms will eventually combine the sample pre-treatment procedure to establish a relatively simple and highly sensitive detection system for heavy metal ions.

重金属是中药的重要污染物之一,重金属含量超标问题是中药安全问题的重要方面，且近年来愈加严峻。针对中药中重金属离子检测的传统方法存在精确度不够高、检测程序繁琐、仪器价格昂贵等缺点。DNA电化学传感技术是一种集成多种技术优势、综合性很强的技术，其能实现对重金属离子等目标物的高选择性高灵敏检测，并具有操作简单快捷和低能耗的优点。本项目基于目标介导DNA构型变化的传感原理，研究设计对重金属离子高特异性响应的DNA电化学传感器，并将其应用于中药中重金属的检测领域。引进分子信标、纳米材料信号放大等方法提高检测灵敏度；采用电化学技术、表面形貌分析手段（如原子力显微镜、扫描电镜等）考查传感器诸项性能，以期在中药重金属成分检测方面有较大突破，最终还拟将该传感平台与样品前处理方法结合起来，建立一套相对简便快捷低成本且高灵敏的重金属离子检测系统。

重金属是中药的重要污染物之一,重金属含量超标问题是中药安全问题的重要方面，且近年来愈加严峻。传统的重金属离子检测方法因存在精确度不够高、检测程序繁琐、仪器价格昂贵等缺点，需要在检测技术和方法上有所突破。本项目基于目标介导DNA构型变化的传感原理，成功建立一系列针对重金属离子检测方法，并将其应用于中药中重金属离子检测体系中。主要完成工作如下：（1）利用依赖铅离子的DNA核酶，结合DNA无酶放大技术产生DNA连环体，构建了一种基于电流响应的铅离子生物传感器。该传感器对铅离子检测限达0.02nM，中药材水提液实际样品检测回收率在95-115%之间；（2）将生物条形码模型与DNA无酶放大技术相结合，构建了一种针对汞离子的生物仿生核酸传感器。该传感器对汞离子检测限低达2.7pM，且Ag+, Pb2+, Zn2+, Cu2+, Cd2+, Ni2+, Fe3+, Al3+ 等离子对检测结果无明显干扰。（3）将对Pb2+特异响应的DNAzyme和DNA无酶放大技术相结合，构建免标记的基于电化学阻抗的Pb2+生物传感器。该项目研究为中药材中重金属离子的检测提供了新的方法和思路，为优化中草药重金属检测技术平台提供前期实验依据与技术支撑。本项目执行期间共发表与本基金项目相关的SCI论文6篇，包括Chem. Commun.（if:6.834）3篇、Analyst (4.023) 1篇，Anal. Method(if: 1.938) 2篇。该项目支助的相关研究获得陈可冀院士-片仔癀药业科研奖励基金一等奖。