Development And Identifying Properties Of The New Type Of Naphthalimida As A Fluorescent Probe On Sulfur-Containing Micromolecule

Objective:To construct a new type of micro-molecules containing sulphur aimed at selectively recognizing the Naphthalimide fluorescent probe and being applied for the examination in the actual biological samples.Method:4-Bromo-1,8-naphthalic anhydride and 4-Chloro-7-nitrobenzofurazan were used as the parent nucleus to synthesize L₁ and L₂,the new-type Naphthalimide fluorescent probe,with two steps by reactions of condensation and Williamson ether synthesis.Meanwhile,L₁ and L₂ were characterized by adopting such modern analytical techniques as ¹H-NMR,¹³C-NMR,HRMS and FT-IR.The recognition performances of L₁and L₂ on such four micro-molecules containing sulphur as hydrogen sulfide,Cysteine,homocysteine and Glutathione organisms were investigated respectively by UV-Visible absorption spectrum and fluorescence spectroscopy in Tris-HCl（pH 7.40）buffer solution.The recognition mechanism of micro-molecules containing sulphur above was explored and probed by HNMR,MS and HPLC.Result:L₁ and L₂,two Naphthalimide fluorescent probes,were verified to be the expected target structure by such modern analytical techniques as ¹H-NMR、¹³C-NMR,HRMS and FT-IR.The findings of recognition performance showed that they responded to such four micro-molecules containing sulphur as hydrogen sulfide,Cysteine,homocysteine and Glutathione organisms in terms of UV-Visible absorption spectrum and fluorescence spectroscopy,and the sample test of which achieved satisfactory results in clinical serum samples,which included as follows.（1）L₁ was presented with unique absorbance enhancement at 576 nm and 421 nm for H₂S and Glutathione respectively.And a distinct fluorescent turn on signal changes at 576 nm for H₂S in Tris-HCl（pH 7.40）buffer solution,which indicated that L₁ could be applied for the selective recognition of hydrogen sulfide and for the restoration of Glutathione by UV-Visible absorption spectrum.At the same time,L₁ was presented with unique absorbance enhancement at 523 nm for homocysteine and Cysteine while Cysteine remained the same but the color of solution changed from colorless to aubergine.Therefore,L₁ could be used to develop a colorimetric test kit for H₂S and cysteine.L₁ can be applied to trace assays of H₂S,glutathione and homocysteine in clinical serum samples.Its spiked recoveries ranged from 93.9%to105.8%,the relative standard deviation（RSG）is less than 7.6%.（2）Similar to L₁,L₂invoked significant changes of UV-Visible absorption spectrum for H₂S and appeared a new but strong UV-Visible peaks at 557 nm while homocysteine,Cysteine and Glutathione triggered an obvious absorbance enhancement at 547 nm and 425 nm respectively,which indicated that L₂ could be used for recognizing Sulfion,Cysteine,homocysteine and Glutathione organisms.L₂ can be applied to trace assays of H₂S,glutathione and homocysteine in clinical serum samples.Its spiked recoveries ranged from 95.3%to102.5%,the relative standard deviation（RSD）is less than 8%.The findings recognition mechanism showed that the reason why L₁ and L₂ recognized S^2-、Hcy and Cys is the chemical response of ether bond cracking in its original structure and that there appeared Thiol rearrangement reaction when recognizing Hcy and Cys.Conclusion:Two new-type Naphthalimide fluorescent probes were simultaneously obtained to quickly test the hydrogen sulfide,Cysteine,homocysteine and Glutathione organisms qualitatively,and could have a recovery of standard addition in serum sample,which has a bright application prospect.