In this study, we report a novel switchable fluorescent nanobiosensor for detection of miRNA. The sensor consists of green-emitting and orange-emitting CdTe QDs exhibiting emission spectra at 525 and 599 nm respectively, under excitation wavelength of 360 nm. Following the addition of miRNA targets to the DNA probes and heteroduplex formation of the hybrid, Green fluorescence CdTe QDs were aggregated and quenched by the DNA/miRNA hybrid via strong interactions at their metal centers. Then, with the addition of orange emitting QDs causes the fluorescence energy transfer to occur and was introduced as a ratiometric approach for miR-155 detection. The relative fluorescence intensity ratio was directly proportional to the concentration of miR-155 from 20 to 100 pM and the detection limit was determined at 14.0 pM. The novel nanobiosensor is “light-on”, rapid, and convenient while it does not require modification or separation procedures and can be applied for the detection of miRNAs in cell lysis with satisfactory results.

在这项研究中，我们报告了一种新型的可切换荧光纳米生物传感器，用于检测miRNA。该传感器由发射绿色和发射橙色的CdTe QD组成，它们在360 nm的激发波长下分别在525和599 nm处显示出发射光谱。将miRNA靶标添加到DNA探针中并形成杂合体后，绿色荧光CdTe QD聚集并通过DNA / miRNA杂合体在其金属中心的强相互作用被猝灭。然后，通过添加橙色发光QD导致荧光能量转移发生，并被引入作为miR-155检测的比例方法。相对荧光强度比与miR-155的浓度从20到100 pM成正比，检测极限确定为14.0 pM。新型纳米生物传感器是“点亮”的，