Gold nanoparticles‐based fluorescence enhancement of the terbium–levofloxacin system and its application in pharmaceutical preparations

Abstract

A sensitive fluorescence (FL) technique is proposed for the determination of levofloxacin (LVX). The method is based on the fact that the weak FL signal of the Tb(III)-LVX system is strongly enhanced in the presence of gold nanoparticles. Gold nanoparticles were prepared by the citrate reduction of HAuCl(4) and characterized by transmission electron microscopy (TEM). Levofloxacin and Tb(III) ion form a fluorescence complex in aqueous solution, and its maximum emission wavelength was found at 545 nm. Optimal conditions for the formation of the levofloxacin-Tb(III) complexes were studied. Levofloxacin was detected by measuring the FL intensity, which increases linearly with the concentration of LVX in the range 6.2 × 10(-10)-2.6 × 10(-8) mol/L. Recovery of the target analytes was > 96% with good quality parameters: linearity (r(2) > 0.996), limit of detection (LOD) and limit of quantification (LOQ) values 2.1 × 10(-10) mol/L and 7.2 × 10(-10) mol/L, and run-to-run and day-to-day precisions with relative standard deviations (RSDs) around 3%. Thus, the proposed method can be successfully applied to the routine determination of levofloxacin in pharmaceutical preparations.

Gold nanoparticles as sensitive optical probes

“…Several MEF approaches have been developed for enhanced sensitivity in the detection of various analytes such as levofloxacin (LOD, 0.2 nM), Hg 2+ (LOD, 4.5 nM) and β-galactosidase (LOD, 100 nM). [163][164][165] Although MEF allows for improved sensitivity, the enhancement is usually limited to 10 fold.…”

Quinolone Complexes with Lanthanide Ions: An Insight into their Analytical Applications and Biological Activity

“…There is a drastic increase in fluorescence in microheterogeneous organized media rather than homogenous solutions [90,91]; micellar solutions obtained with anionic surfactants have the role of bringing the reactants together by trapping the energy donor inside the micelle and binding the lanthanide ion to its surface [85], enhancing the stability of the complexes and shielding them from quenchers [91]. The same effect can be obtained by using coordination polymer nanoparticles (CPNPs) [92], coordination polymer nanosheets (CPNSs) [93] or nanoparticles (NPs) [84,[94][95][96][97][98][99]. The source of the electromagnetic radiation necessary to obtain the excited state of the ligand is either the Xe lamp of the spectrofluorometer, or a chemical species in an excited state, such as SO 2 * obtained through a chemical reaction (chemiluminiscence).…”

Determination of fluoxetine in pharmaceutical and biological samples based on the silver nanoparticle enhanced fluorescence of fluoxetine–terbium complex

“…In recent years, metal nanoparticles have been introduced in lanthanides luminescence measurements as surface enhancers that can amplify and improve their luminescence (24)(25)(26)(27)(28)(29)(30). Lee et al (27) reported the determination of levofloxacin using gold nanoparticles (AgNP)-enhanced fluorescence of the Tblevofloxacin system. Kamruzzaman et al (25) applied AgNPenhanced fluorescence to the sensing of terbium complex for the sensitive determination of fluoroquinolones.…”