Design And Synthesis Of Chromium Fluorescent Probes Based On PET

The study on fluorescent probes has become one of the hottest research field currently for the relationship between the fluorescence property and the ions concentration, which is fit for the heavy metal detection in real time or in situ for its characteristcs of convenience, shortcut, high sensitivity and selectivity. Based on the principle of PET, two novel fluorescent probes were designed and synthesized:RM and DDP. and their capability of recognition to Cr3+ were also studied in this paper.RM(Rhodamine-Methionine) was designed and synthesized from Rhodamine B. The strong fluorescence was produced by the reaction between Cr+ and the imine N and ester O to break the ring structure of Rhodamine lactam, so Cr3+ was recognized. The results showed that the maximum absorption wavelength of RM in organic solvents had a Einstein shift with the increasing of the polarity, and its fluorescence was nearly uncheckable when RM was dissolved in water. When the RM concentration was 1.0×10-5mol/L, the greatest change of the fluorescence intensity appeared at the reaction time of 30min, the fluorescence intensity increased by 7.19 times, and here the concentration of Cr3+ was 5.0×10-5mol/L. The fluorescence changes of RM to some metal ions were uncheckable except La3+ and Fe3+. And the recognition of RM to Cr3+ was not interfered by the coexisting of a variety of metal ions.DDP was designed and synthesized from 4-nitrophthalic anhydride. The strong fluorescence was produced by the introduction of N.N-dimethyl ethylenediamine to 4-nitrophthalic anhydride and the reaction between Cr3+ and N. so Cr3+ was recognized. The results showed that the maximum absorption wavelength of DDP in organic solvents had a blue shift with the increasing of the polarity, and its fluorescence was very weak when DDP was dissolved in water. When the DDP concentration was 1.0x10-5 mol/L, the greatest change of the fluorescence intensity appeared at the reaction time of 60min, the fluorescence intensity increased by 7.49 times, and here the concentration of Cr3+ was 1.0x10-5mol/L. The fluorescence changes of DDP to some metal ions were uncheckable except Fe3+. And the recognition of DDP to Cr3+ was not interfered by the coexisting of a variety of metal ions.