Effect of Silver Nanoparticles on the Fluorescence Properties of Levofloxacin in the Presence of Yttrium(III) Ions in Aqueous and Micellar Surfactant Media

The effect of silver nanoparticles with an average diameter of 4.3 +/- 1.5 nm, synthesized by the borohydride method, on the fluorescence intensity of the fluoroquinolone derivative, levofloxacin, is studied. It is found that the addition of Y3+ ions to the system levofloxacin-silver nanoparticles increases the intensity of the antibiotic intrinsic fluorescence by 2.5 times. An increase in emission is possible as a result of the formation of a rigid structure of the fluorescent center, as well as the simultaneous action of the surface plasmon resonance of nanoparticles and an external emission source on the fluorophore. Carrying out a complexation reaction in the medium of sodium dodecyl sulfate micelles on the simultaneous presence of silver nanoparticles ensures a fourfold increase in the fluorescence signal because of the self-organization of supramolecular structures in the solution. Fluorimetric procedures for the determination of levofloxacin in natural water and a medicinal preparation are proposed. The linearity range of the calibration graph is 1.0 x 10(-9)-1.0 x 10(-6) \M. The limit of detection is 3.0 x 10(-10) M (3 sigma).