Complexation of amoxicillin by transition metals: Physico-chemical and antibacterial activity evaluation.

Some bacteria have developed resistance to antibiotics that were once commonly used to treat them. Moreover, this resistance has become more and more massive and worrying. During this work, we succeeded in synthesizing "metal-antibiotic" complexes, combining as a ligand for the metals of Cu (II), Zn (II) and Fe (III). These complexes AMX - M (M = Cu, Fe and Zn) were characterized by UV-Vis spectrophotometry, IR spectroscopy, and electrochemical methods. Job's method of continuous variation suggested 1:1 metals to ligand stoichiometry for all amoxicillin complexes. The binding constant/association constant (K) of the AMX with Zn(II), Cu(II), and Fe(III) were found to be 4.46 × 104, 7.17 × 102 and 7.65 × 102 L mol-1, respectively. The IR spectra shows that the ligands coordinated to the metal ions through amino, imino, carboxylate, ß-lactamic and carbonyl groups. The electrochemical results proved that amoxicillin oxidation process can be delayed by transition metal complexation. After, the complex synthesis, the antibacterial activity of ligand and its metal complexes were evaluated against Escherichia. coli bacteria by antibiogram method. The results show that the metal-amoxicillin complexes have better antibacterial activity against Escherichia coli (E. coli) than the free ligand (amoxicillin) due to the AMX protection against oxidation after complexation.

Recent advances in electrochemical sensors for amoxicillin detection in biological and environmental samples.

Amoxicillin (AMX) is among the most successful antibiotics used for human therapy. It is used extensively to prevent or treat bacterial infections in humans and animals. However, the widespread distribution and excess utilization of AMX can be an environmental and health risk due to the hazardous potential associated to its pharmaceutical industries effluents. Besides, their extensive use in food animal production may result in some undesirable residues in food, e.g. meat, eggs and milk. Consequently, at high enough concentrations in biological fluids, AMX may be responsible of various diseases such as nausea, vomiting, rashes, and antibiotic-associated colitis. For this reason, the detection and quantification of amoxicillin in pharmaceuticals, biological fluids, environmental samples and foodstuffs require new electroanalytical techniques with sensitive and rapid measurement abilities. This review discusses recent advances in the development of electrochemical sensors and bio-sensors for AMX analysis in complex matrices such as pharmaceuticals, biological fluids, environmental water and foodstuffs. The main electrochemical sensors used are based on chemically modified electrodes involving carbon materials and nanomaterials, nanoparticles, polymers and biological recognition molecules.

Recent progress in controlling the synthesis and assembly of nanostructures: Application for electrochemical determination of p-nitroaniline in water.

The development of nanoparticle research has grown considerably in recent years. One of the reasons for the considerable current interest in nanoparticles is because such materials frequently display unusual physical (structural, electronic, magnetic, and optical) and chemical (catalytic) properties. The development of nanomaterials is of interest to the scientific community and industrial companies. Different methods (physical, chemical, and biological) allow their manufacture. In particular, a major effort has been devoted to the development and improvement of synthesis methods in order to obtain nano-objects of controlled size and shape, a necessary pre-requisite to their organization, and to the study of their intrinsic and collective properties. Reviews play an important role in keeping interested parties up to date on the current state of the research in any academic field. This review aims to focus on the development of nanoparticles and stabilization with adsorbed/covalently attached ligands in solution phase since these factors are deeply related to the origins of the particles' stability, the media to which they are exposed, and the involved applications. This study also examines the factors that influence the synthesis of nanoparticles. It aims to provide an overview of existing electrochemical sensors, particularly those that operate with nanomaterial-based electrode modifications for p-nitroaniline (PNA) determination and to propose guidelines for related research and development activities. Emphasis was placed on the procedure for the analysis of PNA in water samples using nanosilver-based electrodes.