基于可调控DNA-纳米晶微电解体系的中药中重金属多残留电化学快速检测技术研究

Chinese medicines made great contributions to the health of people and prosperity of Chinese economy. The quality and safety control becomes an important issue in the globalization and modernization of Chinese medicines. The investigation reveals that heavy metal contamination in Chinese Medicine and preparations could be a serious health risk to human as well as other organism, and the heavy metals are occurred during stage of planting, circulation and storage and concocted processing. Various analytical methods for the determination of heavy metals in Chinese medicines including inductively coupled plasma massspectrometry (ICP-MS), Atomic Absorption Spectroscopy (AAS) and High Performance Liquid Chromatography (HPLC) have been reported, which are tedious, expensive and time-consuming. Besides, some fast screening method, such as test strip and kit cannot use in the complex matrix of Chinese medicines. So, it’s urgency to develop a simple and reliable method for the fast screening of heavy metals in Chinese medicines and preparations, to timely monitor heavy metals contamination level and assess the potential health risk to human. . In this project, Hg and Pb are selected as the main object due to high toxicity, low content and easy contaminated in medicines, and a new rapid screening electrochemical technique was proposed based on a controlled DNA-nanocrystalline micro-electrolysis system. Three aspects of fundamental issues are focused in this program: 1) To study the steric hindrance effect of T-Hg-T and G-Pb-tetramer, and to precisely control the number of effective targets in the assembly process of DNA- nanocrystalline by multi-disciplinary technologies such as molecular biology, optics, chemistry and analysis, so as to form a DNA-nanocrystalline micro-electrolytic sensing system, and finally construct the electrochemical characteristic fingerprint of Pb and Hg in the micro-electrolytic system. 2) The interference mechanism and damage degree of DNA-nanocrystalline micro-electrolytic sensing system caused by alkaloids, saponins, volatile oils, amino acids, macro/trace elements in the matrix of Chinese medicine were revealed by SECM technology, so as to ensure the accuracy and reliability of the detection results. 3) SPSS software was used to compare the results between the rapid screening system and ICP-MS to confirm the applicability and accuracy of the established system in Chinese medicinal materials. The implementation of this original analysis system with the simple, fast, reliable, accurate and high sensitivity would be very valuable for heavy metals analysis in Chinese medicine and preparation, and thus has both theoretical and practical significance in preventing heavy metal pollution and ensuring the quality of Chinese medicine and preparation in every circulation links of whole industry chain.

中药中痕量残留重金属及复杂基质的干扰给快检技术提出了较高挑战。本项目拟针对Hg和Pb等毒性大、易污染中药材的重金属，首次构建基于可调控DNA-纳米晶微电解体系的中药重金属多残留电化学快速检测新技术，主要研究如下：1）结合分子生物学、光学、化学和分析学等技术手段，以具有特异识别能力的DNA链T-Hg-T和G-Pb-四聚体为载体，深入研究其空间位阻效应，基于微区电化学扫描（SECM）技术精准调控DNA-纳米晶的有效靶点，提高该微电解体系的灵敏度，刻画Pb和Hg基于该微电解体系的电化学特征图谱；2）通过SECM技术实时反馈中药材复杂基质成分对DNA-纳米晶的干扰机理及损伤程度，优化基质前处理技术，高效富集重金属并规避基质干扰成分；3）采用SPSS统计软件，对比新技术与ICP-MS的结果，确证其在中药材上的适用性和准确性。实施该课题对防止中药重金属污染，保证中药质量和安全具有理论和实际双重意义。

中药材中痕量残留重金属及复杂基质干扰给快检技术提出了较高挑战。本项目针对Hg和Pb等毒性大、易污染中药材的重金属，首次构建了基于可调控DNA-纳米晶微电解体系的中药重金属多残留电化学快速检测新技术，主要研究成果如下：1）结合分子生物学、光学、化学和分析学等技术手段，构建了T-Hg-T和G-Pb-四聚体结构电化学生物传感器，深入研究其空间位阻效应，基于微区电化学扫描技术精准调控DNA-纳米晶的有效靶点，提高了测试的灵敏度、准确性及适用性，得到Pb和Hg基于该微电解体系的2种电化学特征图谱；2）通过SECM技术深入分析了中药材基质成分对DNA-纳米晶的干扰机理及损伤程度，形成多种基于重金属吸附脱除的前处理技术，高效富集重金属并规避基质干扰成分；3）基于ICP-MS建立了中药中多类型重金属及有害元素的分析检测平台，并得到了中药重金属污染的健康风险评估体系，采用SPSS统计软件，对比新技术与ICP-MS的结果，确证上述三种传感技术在中药材上的适用性和准确性。该课题的实施对防止中药重金属污染起到了监督作用，同时保证了全产业链中药的质量和安全。