Rapid detection and identification of microorganisms is a challenging and important aspect in a wide range of fields, from medical to industrial, affecting human lives. Unfortunately, classical methods of microorganism identification are based on time-consuming and labor-intensive approaches. Screening techniques require the rapid and cheap grouping of bacterial isolates; however, modern bioanalytics demand comprehensive bacterial studies at a molecular level. Modern approaches for the rapid identification of bacteria use molecular techniques, such as 16S ribosomal RNA gene sequencing based on polymerase chain reaction or electromigration, especially capillary zone electrophoresis and capillary isoelectric focusing. However, there are still several challenges with the analysis of microbial complexes using electromigration technology, such as uncontrolled aggregation and/or adhesion to the capillary surface. Thus, an approach using capillary electrophoresis of microbial aggregates with UV and matrix-assisted laser desorption ionization time-of-flight MS detection is presented.
N-Methylated bismacrocyclic Cu and Ni complexes were synthesised and structurally characterised in the solid state. Their properties in solution were analysed by using NMR and ESR spectroscopies and electrochemical methods. Face-to-face biscyclidenes linked through polymethylene chains form rectangular boxlike cations. These moieties can host some small guest molecules (water, pi-electron donating compounds) and are stabilised by a shell of neighbouring counterions. For the bismacrocyclic dinuclear complexes containing two nickel or two copper ions, the intramolecular interactions between the metallic centres are strengthened through methylation of the macrocyclic components, as compared with the nonmethylated species. We report the electron coupling created by two unpaired electrons coming from two copper centres observed by ESR spectroscopy. Methylation weakens the electron-acceptor properties of the complexes, which leads to less effective binding of the pi-electron-donating guests. It also increases the stability of the lower oxidation states. In the case of the copper complexes, both Cu(II)/Cu(I) and Cu(II)/Cu(III) reversible one-electron transfers are seen in the voltammograms. These changes in properties are interpreted as the consequences of steric repulsion between the methyl substituents and the macrocyclic ring.
The resistance of pathogenic bacteria to antibiotics has become a serious problem. The emphasis is placed on the development of new, effective antimicrobial strategies. One of them is the use of AgNPs in association with antibiotic drugs. The aim of this study was to obtain silver nanoparticles functionalized with ampicillin and to investigate the mechanism of binding antibiotics to nanoparticle using high-performance liquid chromatography approach. To confirm the occurrence of silver nanoparticles functionalization, FTIR, MALDI-TOF MS, and DLS analysis and zeta potential measurements were performed. Moreover we assessed the antibacterial activity of biologically synthesized nanoparticles functionalized with ampicillin against a range of gram (+) and gram (-) bacteria strains such as Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus epidermidis, and Escherichia coli.
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