Detection and Imaging Application of miRNA in Cells and Living Organisms with Nano-Fluorescent Probes Made by Novel Synthesis Materials

As a kind of rare earth fluorescent material, the rare earth upconversion nanomaterial can be applied in various fields such as biological detection and imaging, solar cells, and safe positioning, which has attracted wide concerns. In this study, the novel material is applied to the preparation of biological nano-fluorescent probes. Due to its broad UV absorption spectrum, cobalt oxyhydroxide is selected and used as a quencher for upconversion nanomaterials. Once the cobalt oxyhydroxide is placed on upconversion nanomaterials, the surface reaction can effectively remove the fluorescence reaction of the upconversion nanomaterial. In terms of the molecular miRNA tests for cells and living organisms, the nano-fluorescent probe can reduce the fluorescence intensity of miRNA, while the control group can finish the normal fluorescence reaction. The designed fluorescent probe can adjust the contents of cobalt oxyhydroxides and cells to regulate the fluorescence intensity. In terms of the miRNA sensitivity tests, the fluorescence intensity detected by the nano-fluorescent probe is significantly lower than that in the control group, which can be observed through the fluorescence recovery tests of the chemical system. After the addition of miRNA obtained from cells or living organisms, the fluorescent probe has apparently changed the fluorescence intensity of miRNA in cells/living organisms. Also, the detection range of miRNA is effectively expanded, i.e., the different concentrations of miRNA can be detected by adjusting the ratio of the components of the fluorescent probes, which indicates the excellent sensitivity of the fluorescent probe in detecting miRNA in cells and living organisms. In terms of the miRNA tests for cells, different degrees of cancer cells are selected. The fluorescent probe can discriminate the concentration of cancer cells according to fluorescence imaging of cancer cells, thereby further explaining that the fluorescent probe has high-sensitivity in bio-detection.