基于适配子技术和纳米材料信号放大系统的ccf-miRNA电化学检测方法研究

The incidence of cancer has been growing rapidly in the global scope. Therefore, early diagnosis of cancer is an important scientific problem which needed to be resolved immediately. MicroRNA (miRNA) is a kind of noncoding RNAs consisted of 18~25 ribonucleotides, which plays important regulation roles in the development of cancer. The level variation of circulating cell-free miRNA (ccf-miRNA) in peripheral blood has been proved to have great clinical significance in early diagnosis of cancer, therefore which can be used as novel tumor markers for diagnosis of cancer. However, current detection techniques have defects, such as poor sensitivity and low through-put. This project will design aptamer probes as recognition elements, and use quantum dots as signal amplification system to develop high sensitivity and selectivity method for miRNA detection. This project will carry out study on construction of effective signal amplification system, and develop novel electrochemistry method. Based on the sensitive and accurate determination of ccf-miRNA, this project will provide new electrochemistry method for sensitive detection of ccf-miRNA. The ultimate goal of this study is to provide innovate technique for early diagnosis of cancer.

肿瘤的早期诊断一直是急需解决的重要科学问题。循环游离miRNA（ccf-miRNA）是新近明确的一类敏感高效的肿瘤标志物，由于ccf-miRNA在外周血中浓度极低，对其进行检测通常需要繁琐的标本处理和扩增步骤。目前ccf-miRNA的检测方法包括Northern Blotting、荧光定量PCR等，这些方法存在着灵敏度低、通量小等问题。本研究拟采用特异性适配子探针作为识别元件，利用功能化纳米材料构建信号放大系统，建立针对ccf-miRNA的快速、高灵敏检测方法。具体实验设计中，通过适配子探针的特异性识别提高检测的特异性；通过纳米金颗粒信号放大复合体提高检测的灵敏度。本研究的最终目标为建立基于适配子技术和纳米材料信号放大系统的ccf-miRNA高灵敏检测体系，实现对ccf-miRNA的高灵敏、特异性检测，为肿瘤的早期诊断提供全新的电化学检测方法。

循环游离miRNA（ccf-miRNA）是新近明确的一类敏感高效的肿瘤标志物，由于ccf-miRNA在外周血中浓度极低，对其进行检测通常需要繁琐的标本处理和扩增步骤。本研究基于适配子和量子点的生物学性能，构建了纳米金颗粒信号放大系统，实现了对ccf-miRNA的高灵敏、快速检测。具体实验设计中，通过适配子探针的特异性识别提高了检测的特异性；通过纳米金颗粒信号放大复合体提高了检测的灵敏度，经验证放大效率可达50倍。本研究所建立的检测方法具有高灵敏、高特异识别的特点，并可应用于其他生物分子的检测，有望为肿瘤的早期诊断提供全新的检测方法。