RESUMEN
In this study, different concentrations (0, 0.02, 0.04, and 0.06 wt%) of Mo doped onto La2O3 nanostructures were synthesized using a one-pot co-precipitation process. The aim was to study the ability of Mo-doped La2O3 samples to degrade toxic methylene blue dye in different pH media. The bactericidal potential of synthesized samples was also investigated. The structural properties of prepared samples were examined by XRD. The observed XRD spectrum of La2O3 showed a cubic and hexagonal structure, while no change was recorded in Mo-doped La2O3 samples. Doping with Mo improved the crystallinity of the samples. UV-Vis spectrophotometry and density functional theory calculations were used to assess the optical characteristics of Mo-La2O3. The band gap energy was reduced while the absorption spectra showed prominent peaks due to Mo doping. The HR-TEM results revealed the rod-like morphology of La2O3. The rod-like network appeared to become dense upon doping. A significant degradation of MB was confirmed with Mo; furthermore, the bactericidal activities against S. aureus and E. coli were measured as 5.05 mm and 5.45 mm inhibition zones, respectively, after doping with a high concentration (6%) of Mo.
RESUMEN
This research work intends to evaluate the photoactivity of calcium oxide (CaO) nanorods (NRs) doped with cellulose nanocrystals (CNCs) and cerium (Ce). CNC-doped CaO and Ce/CNC codoped CaO were synthesized via the sol-gel technique. Structural, optical, morphological, physiochemical, phase constitution, and functional group evaluations were performed. The photodegradation of the prepared nanostructures was analyzed by observing photodegradation of a mixture of methylene blue and ciprofloxacin dye under light irradiation. The photocatalytic activity of the dye was drastically enhanced upon codoping in CaO. For both Escherichia coli and Staphylococcus aureus, statistically significant inhibitory zones (p < 0.05) were achieved in the case of CNCs and pristine and codoped CaO. Furthermore, in silico molecular docking studies (MDS) were accomplished against DNA gyrase from nucleic acid biosynthesis and enoyl-[acyl-carrier-protein] reductase (FabI) from the fatty acid biosynthetic pathway to rationalize the possible mechanism behind these antibacterial activities.
RESUMEN
Various concentrations of Mg-doped ZnO nanorods (NRs) were prepared using co-precipitation technique. The objective of this study was to improve the photocatalytic properties of ZnO. The effect of Mg doping on the structure, phase constitution, functional groups presence, optical properties, elemental composition, surface morphology and microstructure of ZnO was evaluated with XRD, FTIR, UV-Vis spectrophotometer, EDS, and HR-TEM, respectively. Optical absorption spectra obtained from the prepared samples showed evidence of blueshift upon doping. XRD results revealed hexagonal wurtzite phase of nanocomposite with a gradual decrease in crystallite size with Mg addition. PL spectroscopy showed trapping efficiency and migration of charge carriers with electron-hole recombination behavior, while HR-TEM estimated interlayer d-spacing. The presence of chemical bonding, vibration modes and functional groups at the interface of ZnO was revealed by FTIR and Raman spectra. In this study, photocatalytic, sonocatalytic and sonophotocatalytic performance of prepared NRs was systematically investigated by degrading a mixture of methylene blue and ciprofloxacin (MBCF). Experimental results suggested that improved degradation performance was shown by Mg-doped ZnO NRs. We believe that the product synthesized in this study will prove to be a beneficial and promising photocatalyst for wastewater treatment. Conclusively, Mg-doped ZnO exhibited substantial (p < 0.05) efficacy against gram-negative (G-ve) as compared to gram-positive (G+ve) bacteria. In silico molecular docking studies of Mg-doped ZnO NRs against DHFR (binding score: - 7.518 kcal/mol), DHPS (binding score: - 6.973 kcal/mol) and FabH (- 6.548 kcal/mol) of E. coli predicted inhibition of given enzymes as possible mechanism behind their bactericidal activity.
RESUMEN
Nanosized tin oxide was fabricated with a simple and cost-effective precipitation technique and was analyzed by performing x-ray powder diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, high-resolution transmission electron (HR-TEM) microscopy, energy-dispersive x-ray (EDX) and UV-Vis spectroscopy. The XRD results revealed that tin oxide particles possessed typical orthorhombic structure and exhibited improved crystallinity with annealing. Calcination at 250 °C produced predominantly orthorhombic SnO which transformed to SnO2 at higher temperatures of 500 and 750 °C. HRTEM and FESEM images showed existence of agglomeration within the particles of tin oxide. The absorption was found to increase up to a certain annealing temperature followed by a decrease, which was recorded via UV-Vis spectroscopy. The effect of annealing temperature on dye decomposition behavior of synthesized photocatalysts was studied. It was noted that annealing temperature affects the size of synthesized particles, band gap width and photoactivity of tin oxide. The sample prepared at 500 °C followed first-order kinetics and exhibited maximum photocatalytic reactivity toward methylene blue. The experimental results obtained from the present study indicate that SnO2 is a promising and beneficial catalyst to remove contaminants from wastewater and environment. The antimicrobial evaluation of SnO annealed at 500 °C against selected targets such as E. coli and S. aureus depicted significant inhibition zones in comparison with 250 and 750 °C samples. Furthermore, molecular docking predictions of SnO2 nanoparticles (NPs) were performed against active pocket of ß-lactamase and DNA gyrase enzyme belonging to cell wall and nucleic acid biosynthetic pathway, respectively. The fabricated NPs showed good binding score against ß-lactamase of both E. coli (- 5.71 kcal/mol) and S. aureus (- 11.83 kcal/mol) alongside DNA gyrase (- 9.57 kcal/mol; E. coli and - 8.61 kcal/mol; S. aureus). These in silico predictions suggested SnO2 NPs as potential inhibitors for selected protein targets and will facilitate to have a clear understanding of their mechanism of action that may contribute toward new antibiotics discovery.
RESUMEN
Nanomaterials are being vigorously investigated for their use in anticancer drug delivery regimes or as biomarkers agents and are considered to be a candidate to provide a way to combat severe weaknesses of anticancer drug pharmacokinetics, such as their nonspecificity. Because of this weakness, a bigger proportion of the drug-loaded nanomaterials flow toward healthy tissues and result in undesirable side effects. It is very important to evaluate drug loading and release efficiency of various nanomaterials to find out true pharmacokinetics of these drugs.This observational study aims to evaluate various surface functionalized and naked nanomaterials for their drug loading capability and consequently strengthens the Reporting of Observational Studies in Epidemiology (STROBE). We analyzed naked and coated nanoparticles of transition metal oxides for their further loading with doxorubicin, a representative water-soluble anticancer drug.Various uncoated and polyethylene glycol-coated metal oxide nanoparticles were synthesized and loaded with anticancer drug using simple stirring of the nanoparticles in a saturated aqueous solution of the drug. Results showed that surface-coated nanoparticles have higher drug-loading capabilities; however, certain naked metal oxide nanoparticles, such as cobalt oxide nanoparticles, can load a sufficient amount of drug.