光控原位合成银/碳纳米复合物及银码信号放大检测miRNA

The expression level of miRNA in the human body is closely related with the critical illness, such as cancer. The common method for miRNA detection has the property of either low sensitivity or complicated process. Therefore, it is a significant work to construct relatively simple method for miRNA examination with high sensitive. In this projiect, silver ions can be reduced to form silver nanoparticles on the surface of carbon nano-material under the irradiation with commonly visible light sources, and in the presence of cooperation reduction reagent. The size，the distribution of the diameter, and the density of the silver nanoparticles covered on the surface of carbon nano-material, can be controlled under different synthesis condition. The probe for miRNA determination, which has the component of silver in the silver/carbon composite nanoparticles act as bio-bar coding, is set up. At the same time, the probe, which contains silver coding and DNA bio-bar coding, is also set up. And it will be applied to detect the miRNA with low concentration. The amplified multiple of the signals will be more remarkable compared with the tradition bio-bar coding method, as there are so many silver nanoparticle per silver/carbon composite nanoparticle that it could be marked with more DNA bio-bar coding or released more silver atoms. A novel method for the synthesis of silver/carbon composite nanoparticles will be developed in this project, which can be controlled by radiation of common visible light source and the technology of in-situ reduction. At the same time, the new strategy can be applied for designing novel bio-bar coding simply and economically. Also, it provids a valuable reference for early diagnosis and treatment of disease.

miRNA在人体中的表达水平与人类重大疾病(如癌症)等密切相关，目前较常用的检测方法要么灵敏度低、要么检测过程繁琐。因此，建立高灵敏且相对简单的miRNA检测方法具有重要意义。本课题拟在协同还原剂和可见光源照射下，通过银离子在羧基化碳纳米材料基质表面被原位还原，获得表面上银纳米粒子尺寸、粒径分布、和覆盖量可控的银/碳复合纳米材料。进一步构建复合纳米粒子中"银"作为"生物条形码"(银码)以及同时含"银码"和DNA条形码的两类探针，并以光谱检测为手段，建立高灵敏、可靠的检测miRNA的分析方法。与传统条形码构建方法相比较，由于单个复合纳米粒子上包含多个银纳米粒子，可标记的DNA条形码或能释放的银原子更多，故信号放大倍数会更显著。该课题可望发展以可见光源和原位还原技术，调控银/碳复合纳米材料性能的方法；同时可提供简单、经济化的生物条形码构建新策略，并为疾病的早期诊断、治疗等方面提供有价值的参考。

重金属离子、生物小分子、MiRNA等在人体中的表达水平与人类某些重大疾病(如癌症)等密切相关，目前较常用的检测重金属离子、生物小分子、MiRNA方法中，要么灵敏度低、要么检测过程或者条件繁琐。因此，建立高灵敏且相对简单的重金属离子、生物小分子、MiRNA检测方法具有重要意义。本课题在立项的基础上，利用氧化还原还原和光源照射下，通过银（金）离子在均相水溶液中、或羧基化碳纳米材料基质表面被还原，获得银（金）纳米粒子尺寸、粒径分布、和光谱特性可控的银（金）纳米（包括纳米簇、纳米片、复合纳米粒子等）材料。进一步以合成的银（金）纳米材料为探针，并以光谱检测等为手段，建立高灵敏、可靠的检测重金属离子、生物小分子、MiRNA的分析方法。建立的方法中大多能实现可视化半定量检测，为重金属离子、生物小分子、MiRNA等的简易检测方法的建立提供了一些新思想和新途径。该课题可提供简单、经济化的检测重金属离子、生物小分子、MiRNA新策略，并为疾病的早期诊断、治疗等方面提供有价值的参考。