The Research Of Fluorescent Probes Based On Quinolin Schiff Base For Aluminium Ions

Aluminum is abundant in the earth,and it plays an irreplaceable role in daily life,industry,agriculture.Once excess,aluminum could not only harm the growth of plants and animals,but could also cause a series of disease for the human body health,such as Parkinson's,Alzheimer's and osteoporosis.Hence,the research on detection methods of aluminum ions has drawn more and more attention of science researchers.Moreover,due to the fluorescence analysis method has the advantages of high sensitivity,high selectivity,simpleness and quickness,it is very important to synthesize highly sensitive and selective fluorescent probes for aluminum ions.This paper has carried out from the following several aspects:1.The introduction of the concept of fluorescence,the mechanism of fluorescence generation and fluorescent probes,and the progress of probes based on quinoline.2.A fluorescent probe QC was synthesized with quinoline derivative and 3,5-dichlorosalicylaldehyde as raw materials.The following conclusions were obtained by UV and fluorescence response experiments of the probe QC and Al³⁺:In the solution of V_??:V_?=1:9and pH=6.00,The probe QC and Al³⁺were complexed with the coordination ratio of 1:1,and the association constant was 1.00×10⁵ M^-1;There was a good linear relationship between the fluorescence intensity of the probe QC and the concentration of Al³⁺?R²=0.9983?in the Al³⁺concentration range of 0-10?M,the detection limit was 0.012?M;Furthermore,other metal ions had no interference on the fluorescence detection of Al³⁺by the probe QC,but the anion F-could reverse the fluorescence of the QC-Al³⁺system.The coordination mechanism of the probe QC and Al³⁺was discussed by nuclear magnetic titration and the fluorescence enhancement mechanism of the probe QC responding Al³⁺might be based on PET mechanism and ESIPT mechanism was proposed.Good results were achieved from the applications of which the probe QC were used for detecting Al³⁺in serum and tap water samples and fluorescence imaging in HeLa cells.3.A fluorescent probe QSH was synthesized with 2-quinoline carboxylic acid and 3,5-ditert-butyl-2-hydroxybenzaldehyde as raw materials.The influences of solvent ratio,pH value,response time and interfering metal ions on the fluorescence intensity of the probe QSH responding Al³⁺were studied,the results showed that the fluorescence enhancement effect of the probe QSH responding Al³⁺was best and wasn't affected by other interfering metal ions in the CH₃OH/H₂O?V/V=2:8,pH=7.0?solution and response time was at least 3 min but no more than 240 min.The stoichiometric ratio of QSH combined with Al³⁺was 1:1 which was confirmed by Job's curve and the complexing constant was 7.70×10⁵ M^-1 that was obtained from the Benesi-Hildebrand equation.Fluorescence titration experiments showed that the fluorescence intensity of QSH-Al³⁺system was linear with the concentration of aluminum ions in the range of 0-1?M,the correlation coefficient was 0.9999 and the detection limit was 0.010?M.The effects of anions?F^-,Cl^-,Br^-and I^-?on the fluorescence of QSH-Al³⁺system were investigated,it was found that only F^-could quench the fluorescence of QSH-Al³⁺system.Good results were achieved from the applications of which the probe QSH were used for detecting Al³⁺in serum and tap water samples and fluorescence imaging in HeLa cells.