基于多维信号和DNA放大的疾病标志物检测新方法研究

Multidimensional signal sensors based on DNA amplification technologies possess the remarkable advantages of multidimensional signal sensing and DNA amplification. By employing the novel multidimensional signal sensors, trace or ultratrace disease biomarkers can be successfully detected with high sensitivity and good accuracy, lending a strong support for the early diagnosis and treatment of malignancy. Therefore, it is very meaningful to construct this type of sensors and to propose novel strategies for disease biomarkers detection. Our project will focus on the following work to fulfill the above aims. The first is to prepare nanomaterials including silver nanoclusters, graphene quantum dot or carbon quantum, and the nanocomposites of graphene/hemin (rGO/Hemin) and molybdenum disulfide/hemin (MoS2/Hemin). The second is to design and synthesize functional organic molecules for preparing functional nanomaterials and clarifying the mechanism of nanomaterial assembling. The third is to design the right DNA sequences for DNA enzymatic digestion and hybridization chain reaction which are initiated by disease biomarkers. The fourth is to construct multidimensional signal sensors including double fluorescent signals, double electrochemical signals and colorimetric-fluorescent signals for the detection of Alpha-fetoprotein, Vascular Endothelial Growth Factor, BRCA1 breast cancer gene and Alkaline Phosphatase. The last is to detect the disease biomarkers in complex biological samples by using the developed methods. Our research will have an important value in providing a new direction in designing high performance sensors for sensitive and accurate detection of disease biomarkers.

DNA放大技术与多维信号传感器的结合，可使检测的灵敏度和准确度显著提高。构建此类传感器并用于检测复杂生物样品中痕量甚至超痕量的疾病标志物，可为疾病早期诊断和治疗提供有力的支持，具有十分重要的研究意义。为此，本项目拟开展以下工作：(1)合成银纳米簇、石墨烯量子点或碳点、石墨烯/血晶素和二硫化钼/血晶素纳米复合物；(2)设计并合成有机功能分子，探索其对纳米材料性能和组装的影响；(3)设计合理的DNA序列，利用疾病标志物诱发酶切DNA放大和HCR放大反应；(4)构建比色-荧光信号、双荧光信号和双电化学信号等多维信号纳米传感器，将其用于甲胎蛋白、血管内皮生长因子、乳腺癌基因序列和碱性磷酸酶等疾病标志物的检测；(5)将所构建的传感器进一步用于实际样品的分析和疾病的诊断。本项目的研究为传感器的构建提出了新的思路，为疾病标志物的准确、灵敏检测提供了新的途径。

通过实验探究及理论计算，对罗丹明荧光探针中杂原子种类、烷基链长度、取代基种类等因素进行了深入的研究，揭示了这些因素对荧光性能和细胞成像的影响，实现了细胞中氢离子和锌离子的选择性检测。设计并合成了具有大斯托克斯位移的三苯胺类聚集诱导荧光探针，对探针荧光性能的影响因素进行了研究，实现了粘度的微观检测。合成了GO/Fe3O4/PpPD、GO/Fe3O4/Au-PmDA、Fe3O4@FeS2、β-MoO3@C等纳米复合物，进行了电化学、形貌、组成等方面的表征，对这些纳米材料的应用进行了探索。设计了基于金纳粒子催化、原位合成银纳米粒子的比色分析体系，实现了肝素和三聚氰胺的灵敏选择性检测。设计了并构建了基于rGO/Hemin 和 GO/PDDA的静电作用的电化学传感器用于焦磷酸根离子检测。由于DNA单双链或DNA碎片所带的负电荷有明显差异，因此该传感策略有望用于构建基于DNA的电化学传感器。基于Cu2+氧化邻苯二胺(OPD)体系构建了检测荧光-比色双信号检测半胱氨酸的新方法。