中文摘要：

目的：建立一种基于纳米粒子的时间分辨（TR）荧光共振能量转移（FRET）生物传感器用于miRNAs的无扩增检测。方法：以寡核苷酸单链probe I偶联GdF3：Tb3＋纳米粒子作为供体，以寡核苷酸单链probe II偶联金（Au）纳米粒子作为受体，利用供体与受体之间的FRET检测目标miRNA hsa-miR-122-5p浓度，并通过设置多功能酶标仪的检测延迟去除自发荧光背景以提高灵敏度。结果：该传感器能够高灵敏度、高特异性地检测目标分子，并且对于光照有良好的耐受性，而且能够避免自发荧光干扰。对hsa-miR-122-5p的检测线性范围为0.1 fmol/L～100 pmol/L，与同类型的RNA荧光传感器的检测限具有可比性。结论：基于纳米粒子的TR-FRET生物传感器用于miRNAs的无扩增检测具有良好的灵敏度和特异性。

英文摘要：

Objective：To develop a miRNA detection method based on the time-resolved （TR） fluorescence resonance energy transfer （FRET） assay. Methods：The GdF3：Tb3＋nanocrystals were coupled with nucleotide probe I as donor, and gold nanocrystals with nucleotide probeⅡas acceptor. miRNA hsa-miR-122-5p was detected by time-resolved FRET assay, and the short lived background luminescence such as auto-fluorescence was suppressed when determining the long lived fluorescence of Tb 3＋by setting appropriate delay time and gate time. Results：The TR-FRET based miRNA sensor was sensitive and selective to hsa-miR-122-5p with a dynamic linear range of 0.1 fmol/L-100 pmol/L, which was compatible with that of the same type of sensors. Furthermore, the GdF3：Tb3＋nanocrystals were stable to light irradiation and their lifetime was long enough to avoid autofluorescence. Conclusion：The TR-FRET miRNA sensor for non-amplification detection of hsa-miR-122-5p based on GdF3：Tb3＋nanocrystals, is sensitive and selective.