基于DNA链置换反应构建通用型生物传感平台及其多元逻辑分析应用

The development of universal biosensing platforms for highly sensitive and selective detection of different kinds of targets is of central importance in clinical diagnosis, genetic analysis, and radiation protection. In this project, we will fabricate universal biosensing platforms and logic gate operations, by designing a novel molecular translator based on DNA strand displacement reaction and combining with autocatalytic DNAzyme-mediated signal amplification. The mechanisms and efficiency of translation will be investigated using circular dichroism spectrum and polyacrylamide gel electrophoresis, etc. By using the proposed molecular translator strategy, we will design two-input (AND and OR) and three-input (AND, OR, and Majority) logic gate operations, then explore the applications of logical analysis in medical diagnosis and radiation damage detection. The nucleic acid targets and non-nucleic acid targets such as mental ions, small molecules, and proteins can be translated into the output DNAzyme sequence by easily altering the correlative function domain. Further developing of the system by using an autocatalytic DNAzyme-mediated cycle can lead to an amplified detection platform. The research findings will be contribute to extend the application of DNA nanotechnology and logical analysis to the construction of universal biosensing platforms, providing a promising strategy for highly sensitive detection of different kinds of targets and accurate diagnosis in biological samples.

发展简单、高灵敏通用型传感平台应用于多种不同类型目标物的分析检测，在疾病诊断、遗传分析和辐射防护等领域具有重要意义。本项目拟基于DNA链置换反应设计新型分子转译器，并与DNA酶自催化循环信号放大方法结合，构建通用型生物传感平台应用于多种不同类型目标物的高灵敏分析检测，研究链置换反应中核酸结构与分子转译器转译机制、转译效率之间的关系及规律。进而基于转译器原理设计二元和三元输入目标的逻辑分析方法，据此发展面向疾病相关标志物的多目标逻辑分析新方法。本项目将基于DNA链置换反应构建的通用型分子转译器设计简单灵活、生物相容性好，与DNA酶自催化循环方法可增强信号等优势结合，能够显著提高传感平台的通用性及灵敏度；利用分子转译器原理发展多目标逻辑分析新方法将为提高疾病诊断准确性作出有益探讨。本项目将拓展DNA纳米技术和多元逻辑分析方法在生物传感研究领域中的应用，有望实现实际样品中疾病相关标志物分析检测。

DNA酶是通过体外筛选技术获得的具有与蛋白酶类似催化活性的单链DNA。DNA酶兼具生物纳米材料单元、生物探针、信号放大原件的多重特点，已经广泛应用于基于DNA纳米技术的生物传感研究中。在本项目的资助下，充分利用DNA酶的三种特性，设计发展了一系列基于DNA酶的不同类型目标分子的生物传感新方法。首先，项目设计的可控沉默DNA酶信标，不但同时具备目标识别和信号放大功能，还可以连续调节DNA酶催化活性，并基于该策略，建立了一种可以检测任意核酸目标的传感方法，为生物传感分析应用提供了新的设计思路。其次，利用DNA酶同时作为识别探针和纳米材料原件，构建了一种一步制备刺激响应型纯DNA水凝胶材料，巧妙地利用构建DNA水凝胶的原材料为信号来源，直接测定DNA水凝胶坍塌所释放出的核酸碎片浓度，实现了金属离子目标的简单、免标记、经济型生物传感分析。因此，本项目研究的工作充分发挥了DNA酶分子构建生物传感平台的优势，有望在各种类型目标的生物传感研究中发挥重要作用。