CdTe@SiO2@PDA复合物的制备与microRNA比率荧光分析

Preparation of CdTe@SiO2@PDA Nanocomposites for Ratiometric Fluorescence Analysis of microRNA

中文关键词: miRNA检测  聚多巴胺  二氧化硅  CdTe量子点  比率型荧光分析

英文关键词: miRNA detection  PDA  silica  CdTe QDs  ratiometric fluorescent analysis

中文摘要:

      目的：基于CdTe@SiO2@PDA纳米复合物构建了一种以CdTe量子点荧光为内参比，SYBR Green Ⅰ（SG Ⅰ）染料的荧光为输出信号的非标记型比率荧光探针，用于microRNA的比率荧光分析。方法：通过控制正硅酸四乙酯（TEOS）和氨水的加入量，使CdTe@SiO2的二氧化硅层厚度在20 nm到80 nm范围内可调，并根据最大荧光保留比优化出二氧化硅层的最佳厚度。结果：CdTe@SiO2@PDA纳米复合物的二氧化硅层最佳厚度约50 nm，以miRNA-155为分析模型，该探针在0.1~10 nM范围内具有良好的线性，检测限为0.1 nM。结论：该分析平台集合了非标记型荧光探针的简单易合成，及比率型荧光探针的信号可信度高的优势，为miRNA的分析检测提供了新方法。

英文摘要:

      Objective: Based on CdTe@SiO2@PDA nanocomposites, a label-free ratiometric fluorescent probe was constructed, which took the fluorescence of CdTe quantum dots as the reference signal and the fluorescence of SYBR Green Ⅰ (SG Ⅰ) as the output signal for microRNA(miRNA) detection. Method: By adjusting the concentration of tetraethyl orthosilicate (TEOS) and aqueous ammonia, the thickness of SiO2 layer was adjustable from 20 nm to 80 nm. According to the maximal fluorescence residual, the optimal thickness of SiO2 layer was optimized. Results: The optimal thickness of SiO2 layer was optimized to be about 50 nm. miRNA-155 was used as an analytical model and the probe had good linearity in the range of 0.1~10 nM, and the LOD was 0.1 nM. Conclusion: The analysis platform integrates the advantages of simple synthesis and easily available materials of label-free fluorescent probes, as well as the high signal reliability of ratiometric fluorescent probes, which provides a new method for the analysis and detection of miRNA.