非晶Fe@SiO2与Au的纳米耦合体系用于循环肿瘤DNA的特异性识别

Detection of circulating tumor DNA（ctDNA）could provide a convenient, specific and non-invasive liquid biopsy technique for the clinical cancer diagnosis, prognosis and follow-up tracking, it has important clinical value. New methods of accurate and efficient exploration on ctDNA testing are the current hot topic. Because of the cumbersome preprocessing step of the polymerase chain reaction (PCR) and sequencing of the gene testing technology and the high probability of false positive, this project proposes to construct a nano-detection system consisting of the DNA-labeled amorphous iron and gold binanoparticles. First, the reasonable designed surface-modificated binano DNA probes are used to be complementary to the target DNA for keeping highly specific of the detection. Then, the amorphous iron nanoparticles with fast magnetic response of circulating tumor DNA are used to realize the magnetic separation and enrichment, to avoid the cumbersome process of PCR and gene sequencing. This solves the problem how to detect in the low concentration of circulating tumor DNA. Amorphous iron nanoparticles and gold nanocrystals coupling by ctDNA and transmission electron microscopy combined with Lorenz, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS), is expected to achieve rapid, high sensitivity ctDNA and accurate identification，application of liquid biopsy technique with ctDNA detection in the diagnosis and treatment of tumor.

循环肿瘤DNA(ctDNA)的检测可为癌症的早期诊断、治疗监测及预后评估提供便捷、安全、无创的检测手段，具有重要的临床应用价值。针对当前基于聚合酶链式反应（PCR）和基因测序的ctDNA检测技术预处理步骤繁琐，假阳性几率高等问题，本项目提出构建具有ctDNA快速、精准识别功能的双纳米颗粒耦合体系。通过两种纳米颗粒表面修饰的捕捉DNA与ctDNA互补配对，以保证识别的高度专一性；制备高磁导率、快速磁响应的非晶铁@SiO2对ctDNA进行高效磁性分离与富集，避免繁琐的PCR扩增与基因测序过程，克服ctDNA因低浓度无法检测的难题。非晶铁@SiO2、Au纳米颗粒通过ctDNA发生特异性耦合，并结合洛伦兹透射电镜、基质辅助激光解吸电离飞行时间质谱和电感耦合等离子体质谱等技术，有望实现ctDNA的快速、特异、高灵敏度检测，推动基于ctDNA检测的液体活检技术在肿瘤诊疗中的应用。

循环肿瘤DNA(ctDNA)的检测可为癌症的早期诊断、治疗监测及预后评估提供便捷、安全、无创的检测手段，具有重要的临床应用价值。针对当前基于聚合酶链式反应（PCR）和基因测序的ctDNA检测技术预处理步骤繁琐，假阳性几率高等问题，本项目构建了具有ctDNA快速、精准识别功能的双纳米颗粒耦合体系。通过两种纳米颗粒表面修饰的捕捉DNA与ctDNA互补配对，保证识别的高度专一性；制备了高磁导率、快速磁响应的非晶铁@SiO2对ctDNA进行高效磁性分离与富集，避免繁琐的PCR扩增与基因测序过程，克服ctDNA因低浓度无法检测的难题。非晶铁@SiO2、Au纳米颗粒通过ctDNA发生特异性耦合，并结合洛伦兹透射电镜、基质辅助激光解吸电离飞行时间质谱和电感耦合等离子体质谱等技术，初步实现了ctDNA的快速、特异、高灵敏度检测，推动基于ctDNA检测的液体活检技术在肿瘤诊疗中的应用。