高性能单颗粒LSPR/SERS光学探针的构建及其在肿瘤核酸标志物联合检测中的应用

Malignant tumor (cancer) is one of the terrible disease of human being, which seriously threatens human health and life. In China, lung cancer has occupied the first place of incidence and mortality of malignant tumour. Detection of cancer at the early stage is one of the important means to improve the cure rate. With the development of molecular biology and medical research, improving the sensitivity and specificity in early diagnosis of tumors has turned to tumor markers. It is significant to build bionanoprobes with high sensitivity and to combine with reliable analytical techniques for detect of tumor biomarkers. Aiming to the significant demand for the early detection of lung cancer,.this project intends to use the tetrahedron-structured DNA (tsDNA) modified Au@Ag NCs as the main tool to build single nanoparticle LSPR(localized surface plasmon resonance ) /SERS (surface-enhanced raman scattering) optical probes, and combine with the signal amplification effect of metal nanoparticles to perform highly sensitive, specific joint detection of the markers (miR-21) of lung cancer in serum by use in situ multi-functional micro zone spectrum analysis system. A novel biosensor based on high-performance single nanoparticle LSPR/SERS optical probes maybe offers an opportunity for applying in cancer diagnosis.

恶性肿瘤是严重威胁人类健康和生命的重大疾病之一，其中肺癌已占据我国恶性肿瘤发病率和死亡率首位。早期发现和诊断是提高癌症治愈率最有效的手段之一。伴随分子生物学和医学研究的发展，发现提高肿瘤早期诊断的敏感性和特异性已经转向肿瘤标志物。构建高灵敏、特异性的生物识别探针并结合可靠的分析方法，是实现肿瘤标志物高灵敏检测的前提。本项目立足于肺癌早期诊断的重大需求，拟以四面体纳米结构DNA（tsDNA）功能化的金银核壳纳米立方体（Au@Ag NCs）为主要工具，构建单颗粒LSPR/SERS光学探针，并利用金属纳米颗粒的信号放大作用，实现肿瘤标志物（miR-21）的高灵敏和特异性检测。从实际应用的角度出发，利用原位多功能微区光谱分析系统，借助高灵敏的LSPR光谱和SERS光谱分析技术对miR-21的联合检测，提高肿瘤早期筛查的准确性。为肺癌早期检测和诊断提供有效的检测分析手段和新的科学思路。

面向解决肺癌临床最迫切的早期检测问题，本项目设计了四面体纳米结构DNA（tsDNA）修饰的单颗粒金银核壳纳米立方体（Au@Ag NC）探针，并基于此探针构建了等离子体纳米生物传感器用于单分子水平分析肺癌核酸标志物（miR-21）。单个miR-21与tsDNA的杂交过程引起Au@Ag NC的散射光谱峰发生了约0.4 nm的红移。我们构建的等离子体纳米生物传感器实现了对miR-21的高灵敏、高特异性检测，检测限为1 aM，检测动态范围从1 aM到1 nM；并且实现了对单碱基错配的microRNA家族的有效区分。此外，通过对模拟实际体系（血清样本）中miR-21的检测，进一步证明了本项目所构建的单颗粒光学探针和检测方法具有应用于临床样品检测的潜力，提高肺癌早期检测和诊断的准确性。

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