title: Spectral properties of the association nanoparticle system of ciprofloxacin-phloxine and its application to fluorescence analysis.
abstract: There is a fluorescence peak at 570 nm, and a maximum absorption peak at 560 nm for phloxine (PHLO) in a pH 7 water solution. Under these conditions, the ciprofloxacin cation (CPFX+) and PHLO- combine into hydrophobic CPFX-PHLO association molecule by means of static gravitation. There are stronger van der Waals forces and hydrophobic forces among the CPFX-PHLO molecules. Thus, they aggregate automatically to the (CPFX-PHLO)n association nanoparticle in red-violet color. That was characterized by scan electron microscopy (SEM), hyperfiltration and dialysis tests. In 0.04 M HCl, the red-violet nanoparticles exhibited a Rayleigh scattering peak at 470 nm, a resonance scattering peak at 580 nm, a maximum absorption wavelength at 565 nm, and a fluorescence peak at 450 nm. The fluorescence analytical conditions of CPFX have been considered. The CPFX concentration in the range of 1.0 x 10(-6)-4.0 x 10(-5) M is linear to the fluorescence intensity, F450nm. The detection limit was achieved at 4.0 x 10(-7) M CPFX. The CPFX in real samples was determined with satisfactory results.
authors.affiliation: Guilin Sajin Pharmceutical Company Group, Guilin 541004, China.
authors.forename: Jieming
authors.initials: J
authors.lastname: Zou
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Jiang
authors.forename: Lisheng
authors.initials: L
authors.lastname: Wang
authors.forename: Tingsheng
authors.initials: T
authors.lastname: Li
authors.forename: Qinye
authors.initials: Q
authors.lastname: Liu
mesh_terms: D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D010316:Particle Size; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence / Q000379:methods*