高灵敏和高选择性的分析检测核酸在临床诊断、遗传分析、环境监测和生物反恐等诸多领域均有重要意义。本项目首次提出以DNA自组装不同结构的纳米材料作为信号放大元件，构建实时在线、免标记、高灵敏、高选择性的耗散型石英晶体微天平(QCM-D)核酸生物传感平台，研究DNA自组装纳米材料的结构与传感信号放大之间的机制及规律。以静电纺丝技术在QCM电极表面修饰具有三维网状结构的纳米纤维膜，进一步提高传感体系的传质速率及灵敏度。据此发展面向肿瘤和遗传疾病相关特定核酸序列的传感分析新方法。本项目将DNA纳米材料的高生物亲和性、高水溶性、设计简单灵活等特点，与QCM-D传感技术的实时在线、免标记等优势相结合构建新型核酸生物传感平台，克服了传统方法信噪比相对较低及标记步骤复杂等不足。本项目将拓展DNA纳米材料和QCM-D技术在生物传感研究领域中的应用，并有望实现实际样品中肿瘤和遗传疾病相关特定核酸序列的分析检测。

The sensitive and selective detection of nucleic acids is important in clinical diagnosis, genetic analysis, environmental monitoring, and biodefense applications. In this project, we will design and fabricate a biosensing platform of quartz crystal microbalance with dissipation monitoring (QCM-D) for real-time, on-line, and label-free detection of nucleic acids using self-assembled DNA nanomaterials as signal amplifiers. The mechanisms of recognition and self-assembled DNA facilitated signal amplification will be investigated using atomic force microscopy and gel electrophoresis, etc. To further improve sensing sensitivity and speed, electrospinning technique will be applied to prepare nanofibrous film with 3D network structure and a large surface area-to-volume ratio on the surface of QCM-D gold electrode. Based on the above research results, we will develop new analytical methods with high sensitivity and selectivity for tumors and hereditary diseases-related specific nucleotide sequences. This novel biosensing platform for nucleic acid combines high biocompatibility, good water-solubility, easy designability and predictability of DNA nanomaterials with real-time, on-line and label-free detection of QCM-D technology, which can circumvent the disadvantages of traditional analytical methods such as relative lower signal-to-noise ratio and complicated functionalization procedure. The research findings will be contribute to extend the application of DNA nanomaterials and QCM-D technology to the construction of biosensing platforms, providing a promising strategy for highly sensitive detection of the specific nucleotide sequences in biological samples.