Synthesis And Properties Of Novel Design Rhodamine Metal Ion Fluorescent Probes

Iron is the most abundant transition metal in the human body, which is involved in numerous cellular processes from metabolism, electron transport, and DNA synthesis. Cells must carefully control iron levels, distribution, and speciation. Disruption of iron regulation can induce serious body function disorders which further cause some diseases. Hg²⁺ is highly toxic, widely distributed in the environment, and bio-accumulates through the food chain. Adverse role of mercury on human physiology on prolonged exposure was realized over the years and now mercury is being considered as one of the most potent neurotoxins for humans and mammals. Therefore, the development of analytical method for the selective and sensitive detection of in biological inside or outside and environment has been a very important research topic. In this paper, we used rhodamine as the fluorescence chromophone, then have synthesized eight different fluorescent probes R1, R2, G2, G4, J1-J4 for detecting metal ion (Hg²⁺, Fe³⁺), The main contents of this paper include:?1?The synthesis and characterization of probes. With the rhodamine spirolactam-ring leuco system as a template,8 new kinds of fluorescent probes were designed. All of unknown compounds were characterized by HRMS,¹H NMR,¹³C NMR, IR and X-Ray.?2?The spectrum properties of probes. The spectrum properties of R1, R2, G2, G4, J1-J4, including selectivity, anti-interference, concentration-gradient curve, Job curve, pH curve and time curve, were study by fluorescence spectrometry. Calculation recognition sites and optimize the structure by the DFT theory. The results show that these probes exhibit high selectivities to Hg²⁺, Fe³⁺ than other metal ions. And the recognition process is quickly, anti-interferent and naked eye visible.?3?The biological properties of probes. The cytotoxicity of the probe R1, R2, G2, G4, J1-J4 was tested by the MTT assay. The probe R1 has been applied to indentify Hg²⁺, different concentrations of the probe R2 and G2 have been applied to indentify Fe³⁺ in PC12 and L929 cells imaging experiment, the probeG4, J1-J4 have been applied to indentify Fe³⁺ in L929 cells, finally we selected probe R1, R2 and G2 have been applied for fluorescence imaging in living mice. The result showed that these probes R1, R2, G2, G4, J1-J4 have the advantages of less toxicity, good cell penetrability and very excellent anti-interference ability, can be used to detect and image target ion (Hg²⁺, Fe³⁺) in organism, which has potential application in biological detection.