基于DNA-Hemin精确组装的高效化学发光生物传感新方法研究

Because of their exquisite recognition properties encoded in the specific interaction of Watson-Crick base-pairing, deoxyribonucleic acids (DNAs) can be programmed and assemble with each other in a predictable manner. In this proposal, we aim to accurately assemble the covalent DNA-Hemin adduct through DNA nanotechnology and suggest new chemiluminescence biosensing strategy. DNA-Hemin adduct will be used as building block to build many nanostructured materials. The DNA-Hemin assembly will be used as the chemiluminescence catalyst to investigate the catalytic activity in detail. At the same time, the structures of the DNA-Hemin assembly will be characterized with some techniques (such as FT-infrared spectra and CD spectra). The relationship between catalytic activity and the structure of DNA-Hemin assembly will be explored. Then, we will make full use of the structure-activity relationship of DNA-Hemin assembly to suggest some new strategies for chemiluminescence biosensing. Furthermore, some signal amplification methods will be introduced into the method to improve the sensitivity. This new biosensing method has the advantages of DNA nano technology in molecular recognition, and also has the advantage of chemiluminescence detection. The features make the proposed assay particularly useful in clinical biochemistry laboratory settings. Therefore, the proposal not only will open a new research area for chemiluminescence analysis, but also will be helpful for us to know the activity of peroxidase-mimicking DNAzyme.

在我们多年来化学发光分析及生物传感研究基础上，借鉴前人有关DNA纳米技术和脱氧核酶的研究成果，本项目拟以DNA的生物属性和氯化血红素（Hemin）的催化性能为基础，以DNA-Hemin复合物为构筑单元，利用DNA结构可设计性进行精确组装，得到结构丰富的DNA-Hemin组装体，系统研究各种组装体的催化性能，揭示组装结构与催化活性之间的规律，探索催化型DNA-Hemin分子开关，以化学发光为检测信号构建高效的生物传感新方法。本项目将DNA与Hemin共价结合，既保留了DNA卓越的分子识别功能，又引入了Hemin高效的信号转导功能，实现了识别与信号转导功能的一体化，为生物传感的设计提供一种新思路。这类新型传感既具有DNA纳米技术在分子识别方面的优势，又具有化学发光法在检测方法的优势，为临床医学、食品安全等领域提供新的检测方法。同时，本项目也将丰富脱氧核酶的研究内容，推动化学发光研究向纵深发展。

本项目以提高生物传感灵敏度和准确度为主要研究目标，充分利用DNA分子结构特性，以化学发光和荧光为检测信号，创建了几种高效的生物传感方法。研究发现了氧化型g-C3N4纳米片催化luminol产生辉光型化学发光的现象，提出了一种非原位注样化学发光检测新模式；提出Hemin双标记的新型分子信标，利用Hemin催化特性构建高灵敏的化学发光生物传感；较深入研究了G-三联体/hemin DNAzyme为信号探针的等温信号放大生物传感体系；发现G-四链体二聚体是一种高效增强硫黄素T荧光的核酸结构。研究成果在Analytical Chemistry、Chemical Communication、Sensors and Actuators B等源刊发表学术论文16篇（所发表的论文在SCIE上记录的引用177次）。