Department of Chemistry, University of Kurdistan, Sanandaj, 66177-15175, Iran.
Research Center for Nanotechnology, University of Kurdistan, Sanandaj, 66177-15175, Iran.
Mikrochim Acta. 2018 Jul 11;185(8):372. doi: 10.1007/s00604-018-2868-5.
A 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 MnO nanosheets as the quenching agent. The blue-green fluorescence of the DNA-loaded C-dots is quenched by the MnO 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, with a 600 cells·mL detection limit. The method was applied to the analysis of serum samples spiked with microRNA, and satisfactory results were acquired. Graphical abstract Schematic of a fluorometric sensing platform for miRNA-155. The method relies on a FRET process between C-dots and MnO nanosheets. This strategy has a practical application for detection of miRNA in cell lines and biological fluids.
一种用于灵敏检测 microRNA 的荧光方法。该方法利用负载 DNA 探针的碳点（C-dots）作为荧光团，MnO 纳米片作为猝灭剂。DNA 负载的 C-dots 的蓝绿色荧光被 MnO 纳米片猝灭，但与靶 microRNA-155 结合后恢复。C-dots 的最大激发波长和最大发射波长分别为 360nm 和 455nm。荧光与 microRNA-155 浓度的对数在两个范围内呈线性相关，即从 0.15 到 1.65 aM 和从 1.65 到 20 aM。检测限低至 0.1 aM。该测定法可区分完全互补和单碱基错配的 microRNA。该测定法用于检测 MCF-7 乳腺癌细胞时具有高特异性，可在 1000 至 45000 个细胞·mL 的浓度范围内检测到，检测限为 600 个细胞·mL。该方法已应用于血清样品中 microRNA 的分析，获得了令人满意的结果。荧光传感平台用于 microRNA-155 的示意图。该方法依赖于 C-dots 和 MnO 纳米片之间的 FRET 过程。该策略在细胞系和生物流体中检测 miRNA 具有实际应用价值。
