New Fluorescent Probes Based On Water-Soluble Aminonaphthalimide And Porphrin

In recent years, people have paid much more attention to the study and application of all kinds of fluorescent molecular probes. They have lots of advantages, such as simple operation, low-cost time, great selectivity and high sensitivity and so on. They play a very important role in many aspects such as medicinal science and chemical industry.Naphthalimide derivatives are chosen because they are excellent fluorophores with high quantum yield, high light stability and the large Stokes shifts. However, the probes based on naphthalimide derivatives are commonly applied in organic solutions. Therefore, it’s still a challeng to improve solubility of chemical sensors based on naphthalimide derivatives in water. In this thesis, three novel and water-soluble fluorescent probes were thought and obtained by organic synthesis for the examination of mercury ion, cysteine and pH. The details of the contents are presented:We have synthesized a fluoroionophore based on naphthalimide and used it to determine mercury ion in aqueous solution, which has a pyridine. The detection limit of the probe toward mercury ion is4.93×10-8M, with a linear performance in the concentration scope from2.57×10-7to9.27×10-5M. From the experimental results we can see that pH shows little influence to the determination of mercury ion by this probe in medium condition. And the probe shows great selectivity for mercury ion over any metal cation.We have obtained a probe to determine cysteine in aqueous solution, with a nitrogen-containing2-(piperazine-1-yl-methyl) benzaldehyde. The detection limit of the probe toward cysteine is7.8×10-9M, with a linear performance in the concentration scope from3.9×10-8to1.4×10-5M. And the chemosensor shows great selectivity for cysteine over other amino acids.A new probe with a piperazine based on functionalized naphthalimide has been synthesized and made to determine pH in aqueous solution. It has a linear pH performance scope from3.20to7.80, with a short response time. And common metal ions show little interference to the pH dertermination.Porphyrins are exercellent fluorescent substances because of the high light stability, high quantum yield, larger Stokes shifts, and visable light excitation(longer than400nm). Therefore, we have synthesized and got a silver ion probe based on porphyrin derivative. We have studied the response characteristics of this chemosensor. The detection limit of the probe toward silver ion is5.1×10-8M, with a linear performance in the concentration scope from1.0×10-7to5.0×10-5M. From the experimental results we can see that pH shows little influence to the determination of silver ion by this probe in medium condition. And the fluorescent probe shows great selectivity to silver ion over any metal cation.