Phosphineoxide-Chelated Europium(III) Nanoparticles for Ceftriaxone Detection

The present work demonstrates the optimization of the ligand structure in the series of bis(phosphine oxide) and β-ketophosphine oxide representatives for efficient coordination of Tb³⁺ and Eu³⁺ ions with the formation of the complexes exhibiting high Tb³⁺- and Eu³⁺-centered luminescence. The analysis of the stoichiometry and structure of the lanthanide complexes obtained using the XRD method reveals the great impact of the bridging group nature between two phosphine oxide moieties on the coordination mode of the ligands with Tb³⁺ and Eu³⁺ ions. The bridging imido-group facilitates the deprotonation of the imido- bis(phosphine oxide) ligand followed by the formation of tris-complexes. The spectral and PXRD analysis of the separated colloids indicates that the high stability of the tris-complexes provides their safe conversion into polystyrenesulfonate-stabilized colloids using the solvent exchange method. The red Eu³⁺-centered luminescence of the tris-complex exhibits the same specificity in the solutions and the colloids. The pronounced luminescent response on the antibiotic ceftriaxone allows for sensing the latter in aqueous solutions with an LOD value equal to 0.974 μM.

Carbon Dots Green Synthesis for Ultra-Trace Determination of Ceftriaxone Using Response Surface Methodology

The present study sought to develop a facile and green synthetic approach for producing fluorescent carbon dots (CDs) from a natural biomass using aqueous extraction of carbonized blue crab shell. Spherical carbon dots (6.00 ± 3.0 nm) exhibited an extended emission range with excellent quantum yield (14.5 ± 3.5%). In order to measure ceftriaxone, we offered a simple and sensitive method, based on fluorescence quenching of carbon dots in plasma and water with recovery values of 94.5-104.1%. Furthermore, with usage of central composite design (CCD) based response surface methodology (RSM); we optimized the effect of different factors. In addition, ANOVA evaluated the accuracy and suitability of quadratic model. Under optimal conditions, fluorescence quenching revealed a sensitive response in the concentration range of 20-1000 nM with the limit of detection 9.0 nM for ceftriaxone. Finally, carbon dots-based fluorescence quenching procedure was able to quantify ceftriaxone in plasma, as well as mineral and tap water. Spiked samples achieved satisfactory efficiencies.