Rare Earth Ions - Fluoroquinolones Fluorescence Enhancement Phenomenon And Its Analytical Applications

The quinolones are a family of recently synthesized antibiotics. They originate from nalidixic acid (discovered in 1962) and their activity is based on the inhibition of bacterial DNA gyrase, being effective against gram-negative aerobic bacteria. From the second generation, the addition of fluor and other substitutes gave rise to the fluoroquinolones, improving their power and spectrum for activity and expanding their coverage to anaerobic gram-positive bacteria. Currently, they are widely used in clinic.Rare earth complexes with organic ligands often show strong efficient fluorescence. In recent years, there is considerable interest in the study on these complexes for their potential application for determination of the rare earth elements, or conversely, for determination of the organic ligands, or as fluorescent probes in clinical chemistry and molecular biology, and environmental sciences.In this paper, the fluorescence characteristics of the PZFX-Eu and BLFX-Eu complex were studied. The fluorescence system was optimized by introduction of surfactant, synergic ligands and certain rare earth ions. The above fluorescence system was applied to determine the PZFX, BLFX and europium in synthetic rare earth oxides with satisfactory results. The sensitization mechanism was also studied.In the first section, we summarize the mechanism and progress of fluorescent probe of rare earth ions and the main determination methods of fluoroquinolones.In the second section, the PZFX-Eu fluorescence system was studied in detail. PZFX-Eu-SDBS, PZFX-Eu-SDS and PZFX-Eu-SDS-phen fluorescence system was set up. It is found that the anionic surfactant SDBS and SDS could greatly increase the fluorescence of the system. The introduction of synergic ligands can also enhance sensitivity. It can be concluded that in the micellar solutions the complex of PZFX-Eu could emit the characteristic peak of Eu³⁺ by intermolecular energy transfer. The high selective and sensitive fluorescence system was used for determination of PZFX and europium in rare earth samples with satisfactory results. The recovery of PZFX was in the range of 90%-110% with a diction limit of 2.0×10^-10mol L^-1. Under optimum...