Design And Synthesis Of Pyrene, Fluorescein And Rhodamine B-based Fluorescent Probes For Selective Detection Of Metal Ion

Fluorescent probe, the fluorescent sensors, is a new chemical detection method with high sensitivity and specific selectivity, low dosage and easy operation, and has important applications in analytical chemistry, biochemistry, environmental science and clinical. Most of the autofluorescence of biological molecules have weak fluorescence or non-fluorescence, and the detection sensitivity is poor. Now the labeling reagents of strong fluorescent is used to label the substance for producing a higher intensity of fluorescence material. Thereby, the advantage of the fluorescence probe technique is reducing the detection limit greatly. In recent years, more and more attention is paid to the development and design of the fluorescent probes.The paper includes the following three parts:Firstly, the fluorescent probe PYPA with pyrene as light group is designed. After synthesis and separation, the structure of the PYPA is detected by 1H NMR, 13 C NMR and HRMS, finally the probe is used to detect metal ions. The PYPA is found that it can detect Zn²⁺ from the solution of methanol/water（OHMe OH2/VV =3/2, HEPES buffer, 1.0 m M, p H=7.2） in the presence of PPi. Probe PYPA, Zn²⁺ and PPi are complexed by 2:2:1. The binding constant K a=3.343×105 M^-1 and the detection limit is 0.030 μM.Secondly, the fluorescent probe FLTC with fluorescein as light group is designed. After synthesis and separation, the structure of the FLTC is detected by 1H NMR, 13 C NMR and HRMS, finally the probe is used to detect metal ions. Finally, the fluorescence experiments of the probe FLTC is studied. The FLTC is found that it can detect Hg²⁺ exclusively from the solution of ethanol/water（OHEt OH2/ VV =3/2, HEPES buffer, 0.5 m M, p H=7.15）. Probe FLTC and Zn²⁺ are complexed by 1:1. The binding constant K a=2.2078×104 M^-1 and the detection limit is 0.21 μM. The difference is that FLTC can also detect Ag + in the presence of Hg²⁺.Thirdly, the fluorescent probe RBTA with rhodamine B as light group is designed. After synthesis, the structure of the RBTA is detected by 1H NMR, 13 C NMR and MS, Then the fluorescent and UV-vis experiments of the probe RBTA is studied. The RBTA is found that it can detect Fe³⁺ and Sn²⁺ from the solution of ethanol/water（HOHEt O2/ VV =3/2, HEPES buffer, 0.5 m M, p H=7.10）. Probe RBTA bind with Fe³⁺ and Sn²⁺ by 1:1 from the Job’s plot experiment. The binding constant K a=3.26×103M^-1(Fe³⁺) and 7.61×103(Sn²⁺), and the detection limit are 0.008 μM(Fe³⁺) and 0.003 μM(Sn²⁺).