| Fluorescent probes are widely used in biomedical and environmental aspects because of their high selectivity, high sensitivity and biological compatibility. Near-infrared (650-900 nm) light have longer wavelength in absorption and fluorescence emission and produce lower interference background fluorescence and penetrate much deeper into tissues than UV and visible light. So researching near-infrared fluorescent probes is a very meaningful work.In this thesis, two near-infrared naphthofluoresce-based fluorescent probes were designed and synthesized for Cys and SO32-, respectively. Probe 1 was synthesized by acryloyl chloride and naphthofluoresce throught substitution reaction and its structure was confirmed by 1H NMR,13C NMR, MS and HR-MS. Its sensing properties and potential applications were studied. We found that probe 1 could rapidly, selectivitely detecte cysteine (Cys) over various analytes including the similar structured homocysteine (Hcy) and glutathione (GSH). Probe 1 is a good colorimetric fluorescent molecule. The detection limit of probe 1 for Cys is found to be about 0.18 μM, which is much lower than the reported intracellular concentration of Cys (30-200 μM).In addition, this probe was successfully applied to bioimage intracellular Cys in living cells with low cytotoxicity.Probe 2 was synthesized by naphthofluoresce and levulinic acid through esterification reaction. The compound structure was also comfirmed by 1H NMR,13C NMR, MS and HR-MS. After a detailed sensing properties exploration of probe 2, we found prode 2 shows rapid response, high selectivity for SO32- and causes distinct color changes and significant NIR fluorescence turn-on responses. The detection limit of probe 2 for SO32- is found to be about 1.744 μM. In addition, this probe can be used for imaging of SO32- in living cells, indicating that this probe shows great potential for applications in biological samples. |
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