Showing papers by "Wael H. Eisa published in 2023"

Synthesis, Characterization, and Docking Study of Novel Thioureidophosphonate-Incorporated Silver Nanocomposites as Potent Antibacterial Agents

Abstract: Newly synthesized mono- and bis-thioureidophosphonate (MTP and BTP) analogues in eco-friendly conditions were employed as reducing/capping cores for 100, 500, and 1000 mg L−1 of silver nitrate. The physicochemical properties of silver nanocomposites (MTP(BTP)/Ag NCs) were fully elucidated using spectroscopic and microscopic tools. The antibacterial activity of the nanocomposites was screened against six multidrug-resistant pathogenic strains, comparable to ampicillin and ciprofloxacin commercial drugs. The antibacterial performance of BTP was more substantial than MTP, notably with the best minimum inhibitory concentration (MIC) of 0.0781 mg/mL towards Bacillus subtilis, Salmonella typhi, and Pseudomonas aeruginosa. Among all, BTP provided the clearest zone of inhibition (ZOI) of 35 ± 1.00 mm against Salmonella typhi. After the dispersion of silver nanoparticles (AgNPs), MTP/Ag NCs offered dose-dependently distinct advantages over the same nanoparticle with BTP; a more noteworthy decline by 4098 × MIC to 0.1525 × 10−3 mg/mL was recorded for MTP/Ag-1000 against Pseudomonas aeruginosa over BTP/Ag-1000. Towards methicillin-resistant Staphylococcus aureus (MRSA), the as-prepared MTP(BTP)/Ag-1000 displayed superior bactericidal ability in 8 h. Because of the anionic surface of MTP(BTP)/Ag-1000, they could effectively resist MRSA (ATCC-43300) attachment, achieving higher antifouling rates of 42.2 and 34.4% at most optimum dose (5 mg/mL), respectively. The tunable surface work function between MTP and AgNPs promoted the antibiofilm activity of MTP/Ag-1000 by 1.7 fold over BTP/Ag-1000. Lastly, the molecular docking studies affirmed the eminent binding affinity of BTP over MTP—besides the improved binding energy of MTP/Ag NC by 37.8%—towards B. subtilis-2FQT protein. Overall, this study indicates the immense potential of TP/Ag NCs as promising nanoscale antibacterial candidates.

Solid waste-supported nickel nanoparticles; a sustainable, recoverable, and efficient heterogeneous catalyst for organic pollutant degradation.

Abstract: The processing of polymeric solid wastes into industrial processes is of outmost importance from an environmental and economic point of view. Herein, a simple and straightforward route was developed for immobilizing nickel nanoparticles on the surface of waste loose fill as a recoverable heterogeneous catalyst. The nickel nanoparticles exhibited a spherical-like shape and were not uniformly dispersed in the loose fill matrix. The carbonyl and/or carboxyl groups would initiate active sites along the loose fill chains, which serve as adsorption centers and tight fixing of nickel ions. The catalytic activity of [email protected] fill nanocomposite was evaluated through the degradation of 4-nitrophenol, reactive blue dye, and mixture of both. The results indicated the catalyst retained 87% of its activity after 20 cycles. The use of a solid waste as a supporting matrix in heterogeneous catalysis may reduce the fabrication cost and improve the contact between the reactants and Ni nanoparticles due to the porosity of loose fill. The use of waste material made from renewable resources (vegetable starch) could explore genuinely and sustainable materials as alternatives to the traditional polymers in heterogeneous catalysis.