基于G-四链体的脱氧核酶催化沉淀放大用于石英晶体微天平核酸传感体系的研究

The specific and sensitive detection of nucleic acid sequences is important in disease diagnosis, genetic risk assessment, environmental monitoring and biodefense. In this project, G-quadruplex-based DNAzyme catalyzed precipitation will be utilized as signal amplifier to fabricate simple, rapid, label-free and sensitive quartz crystal microbalance biosensors for detection of nucleic acids. The influences of DNAzyme composition, reaction substrate and buffer composition on precipition reaction will be researched to optimize the sensing systems and detection procedures, improve signal amplification efficience and decrease the interference from nonspecific precipitation. Then several sensing systems with different design strategies will be fabricated to satisfy various detection demands. The capability of these sensing systems resisting the interferences from complex sample matrix will also be investigated. This research combines the flexibility of G-quadruplex DNA sequences, the catalyzed precipitation ability of DNAzyme with real-time, lable-free detection of QCM technology to fabricate novel biosensing platform for nucleic acids, providing promising extensional application of QCM in biosensing field.

高特异性和高灵敏的核酸序列检测在疾病诊断、遗传风险评估、环境检测和生物反恐等方面都有重要的意义。本项目首次提出以基于G-四链体的脱氧核酶催化的沉淀反应作为信号放大元件，构建简单快速、免标记、高灵敏度的石英晶体微天平（QCM）核酸生物传感平台，研究DNA酶的组成、反应底物、缓冲液组成对于沉淀反应的影响和规律，优化传感体系构建和检测流程，提高检测信号放大效果并降低非特异沉淀的干扰。据此发展多种传感体系构建模式以满足不同的检测需要，并考察这些传感系统应对复杂样品基质的抗干扰能力。本项目将G-四链体 DNA序列的灵活性、DNA酶的催化沉淀能力与QCM的实时在线、免标记等优势结合起来构建新型核酸传感平台，将扩展QCM技术在生物传感领域的应用，并有望实现实际样品中与疾病相关的核酸序列的分析检测。