AbstractA fluorometric method is presented for sensitive deternination of microRNA. It is making use of carbon dots (C-dots) loaded with a DNA probe as fluorophore and MnO2 nanosheets as the quenching agent. The blue-green fluorescence of the DNA-loaded C-dots is quenched by the MnO2 nanosheets, but restored on binding target microRNA-155. The maximum excitation wavelength and the maximum emission wavelength of C-dots are at 360 nm and 455 nm, respectively. Fluorescence correlates linearly with the log of the microRNA-155 concentration in two ranges, viz. from 0.15 to 1.65 aM and from 1.65 to 20 aM. The detection limit is as low as 0.1 aM. The assay can discriminate between fully complementary and single-base mismatch microRNA. The assay displayed high specificity when used to detect MCF-7 breast cancer cells which can be detected in concentrations from 1000 to 45,000 cells·mL−1, with a 600 cells·mL−1 detection limit. The method was applied to the analysis of serum samples spiked with microRNA, and satisfactory results were acquired. Graphical abstractSchematic of a fluorometric sensing platform for miRNA-155. The method relies on a FRET process between C-dots and MnO2 nanosheets. This strategy has a practical application for detection of miRNA in cell lines and biological fluids.

中文翻译：

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基于碳点和二氧化锰纳米片作为供体-受体对的癌细胞中 microRNA-155 的荧光测定

摘要 提出了一种灵敏测定 microRNA 的荧光法。它利用载有 DNA 探针的碳点 (C-dots) 作为荧光团和 MnO2 纳米片作为淬灭剂。载有 DNA 的 C 点的蓝绿色荧光被 MnO2 纳米片淬灭，但在结合目标 microRNA-155 时恢复。碳点的最大激发波长和最大发射波长分别为 360 nm 和 455 nm。荧光在两个范围内与 microRNA-155 浓度的对数线性相关，即。从 0.15 到 1.65 aM 和从 1.65 到 20 aM。检测限低至 0.1 aM。该测定可以区分完全互补和单碱基错配的 microRNA。当用于检测MCF-7乳腺癌细胞时，该测定显示出高特异性，可在1000至45,000个细胞·mL-1的浓度下检测，具有600个细胞·mL-1的检测限。将该方法应用于加标microRNA的血清样品的分析，获得了满意的结果。miRNA-155 荧光传感平台的图形摘要示意图。该方法依赖于 C 点和 MnO2 纳米片之间的 FRET 过程。该策略在检测细胞系和生物体液中的 miRNA 方面具有实际应用。该方法依赖于 C 点和 MnO2 纳米片之间的 FRET 过程。该策略在检测细胞系和生物体液中的 miRNA 方面具有实际应用。该方法依赖于 C 点和 MnO2 纳米片之间的 FRET 过程。该策略在检测细胞系和生物体液中的 miRNA 方面具有实际应用。