A novel isatin Schiff based cerium complex: synthesis, characterization, antimicrobial activity and molecular docking studies.

In this work, a novel isatin-Schiff base L2 had been synthesized through a simple reaction between isatin and 2-amino-5-methylthio-1,3,4-thiadiazole. The produced Schiff base L2 was then subjected to a hydrothermal reaction with cerium chloride to produce the cerium (III)-Schiff base complex C2. Several spectroscopic methods, including mass spectra, FT-IR, elemental analysis, UV-vis, 13C-NMR, 1H-NMR, Thermogravimetric Analysis, HR-TEM, and FE-SEM/EDX, were used to completely characterize the produced L2 and C2. A computer simulation was performed using the MOE software program to find out the probable biological resistance of studied compounds against the proteins in some types of bacteria or fungi. To investigate the interaction between the ligand and its complex, we conducted molecular docking simulations using the molecular operating environment (MOE). The docking simulation findings revealed that the complex displayed greater efficacy and demonstrated a stronger affinity for Avr2 effector protein from the fungal plant pathogen Fusarium oxysporum (code 5OD4) than the original ligand. The antibacterial activity of the ligand and its Ce3+ complex were applied in vitro tests against different microorganism. The study showed that the complex was found to be more effective than the ligand.

Spectrophotometric and Fluorometric Methods for the Determination of Fe(III) Ions in Water and Pharmaceutical Samples.

Chemical sensors based on mesoporous silica nanotubes (MSNTs) for the quick detection of Fe(III) ions have been developed. The nanotubes' surface was chemically modified with phenolic groups by reaction of the silanol from the silica nanotubes surface with 3-aminopropyltriethoxysilane followed by reaction with 3-formylsalicylic acid (3-fsa) or 5-formylsalicylic acid (5-fsa) to produce the novel nanosensors. The color of the resultant 3-fsa-MSNT and 5-fsa-MSNT sensors changes once meeting a very low concentration of Fe(III) ions. Color changes can be seen by the naked eye and tracked with a smartphone or fluorometric or spectrophotometric techniques. Many experimental studies have been conducted to find out the optimum conditions for colorimetric and fluorometric determining of the Fe(III) ions by the two novel sensors. The response time, for the two sensors, that is necessary to achieve a steady spectroscopic signal was less than 15 s. The suggested methods were validated in terms of the lowest limit of detection (LOD), the lowest limit of quantification (LOQ), linearity, and precision according to International Conference on Harmonization (ICH) guidelines. The lowest limit of detection that was obtained from the spectrophotometric technique was 18 ppb for Fe(III) ions. In addition, the results showed that the two sensors can be used eight times after recycling using 0.1 M EDTA as eluent with high efficiency (90%). As a result, the two sensors were successfully used to determine Fe(III) in a variety of real samples (tap water, river water, seawater, and pharmaceutical samples) with great sensitivity and selectivity.

Application of Synthesized Vanadium-Titanium Oxide Nanocomposite to Eliminate Rhodamine-B Dye from Aqueous Medium.

In this study, a V@TiO2 nanocomposite is examined for its ability to eliminate carcinogenic Rhodamine (Rh-B) dye from an aqueous medium. A simple ultrasonic method was used to produce the nanosorbent. In addition, V@TiO2 was characterized using various techniques, including XRD, HRTEM, XPS, and FTIR. Batch mode studies were used to study the removal of Rh-B dye. In the presence of pH 9, the V@TiO2 nanocomposite was able to remove Rh-B dye to its maximum extent. A correlation regression of 0.95 indicated that the Langmuir model was a better fit for dye adsorption. Moreover, the maximum adsorption capacity of the V@TiO2 nanocomposite was determined to be 158.8 mg/g. According to the thermodynamic parameters, dye adsorption followed a pseudo-first-order model. Based on the results of the study, a V@TiO2 nanocomposite can be reused for dye removal using ethanol.

Adsorption Behavior of Congo Red onto Barium-Doped ZnO Nanoparticles: Correlation between Experimental Results and DFT Calculations.

Ba-loaded ZnO nanoparticles (Ba/ZnO) were obtained by the co-precipitation process and employed as a sorbent for Congo Red (C32H22N6Na2O6S2) dye (CR). Physicochemical parameters such as particle size, pH, and contact time were checked to characterize the adsorption process. The maximum adsorption capacity of Ba/ZnO NPs for CR (1614.26 mg/g) proves its potential utility in the elimination of CR dye from wastewater. The adsorption mechanism was studied via infrared spectroscopy and density functional theory calculations. The geometrical parameters and electronic properties of the CR-Ba/ZnO complex, particularly the interaction energy, the density of states, and the charge transfer, highlighted the Ba-ion mediation in the chemical bond formation between CR and the surface. The interaction between CR and Ba-doped ZnO has found to show strong chemisorption with charge transfer between the SO3- group and adsorbed Ba2+ ion on the surface.