Design Of Turn-on Fluorescent Probes And The Application In Detection Of Hydrogen Sulfide And PH

Recent years, fluorescent probes have become an important means of scientific inquiry due to the more and more mature application in detecting and marking. It shows the broad application prospect in many areas, such as environmental protection, chemical, food, biology, medicine, etc.Currently,,the most majority of fluorescent probes have the feature of quantitative detection.While they usually do not have the property of specificly targeting. Physiological process can not be observed by people,Therefore, fluorescent probes which have specific property of targeting is in urgent need.In this paper, we design probes by introducing the other units to modify the structure itself from the inspire of Nile red and fluorescein.We discover that these probes we design have some new features and also can make up for its shortcomings at the same time. In this paper, we design an enhanced fluorescence probe named NRS, after it is affected by hydrogen sulfide, it has a strong fluorescence, and it can be found in the mitochondria of cells.Based on the mechanism of photoinduced electron transfer (PET), the 2,4-dinitrofluorobenzene structure unit was introduced to the Nile red derivative 9-Dimethylamino-2-hydroxy-5H-benzo[a]Phenoxazin-5-one and we build the fluorescent probeNRS. Probe NRS showed excellent features, such as probe NRS can respond rapidly and specificly to hydrogen sulfide when there are other cations, anion, reactive oxygen species and reactive nitrogen species exiting together.It suggests that probe NRS has highly selective response to the hydrogen sulfide. Through the cell dyeing experiments, we found that probe NRS have the permeability of cell membran because it can enter in the cell from outside so that we can find the fluorescence in the mitochondria of cells. Secondly, fixed position test with cell Rhl23 of image further showing that probe NRS have specific property of targeting in the mitochondria of cells.The second part in this paper, we synthesized a kind of pH fluorescent probe FDI which can aim at mitochondria.The probe FDI can quickly locate in the mitochondria and the probe FDI has a longer fluorescence emission spectrum (650-750 nm). The probe can monitor the pH in the cells in a real-time.It can response to the pH rapidly in a wide range.It is very intuitionistic to recgnise the pH, because he probe FDI solutions of different pH have obviously different color change. We also carried on the light stability experiments, the results show that the probe FDI is not easy to decompose under the sunshine. The probe FDI shows good solubility and compatibility in organism in fluorescent laser-scanning confocal microscopy experiment.That also prove this kind of probe has good permeability for cells.