Journal of Colloid and Interface Science, Vol.591, 115-128, 2021
Highly efficient antimicrobial agents based on sulfur-enriched, hydrophilic molybdenum disulfide nano/microparticles and coatings functionalized with palladium nanoparticles
In this research the molybdenum disulfide (MoS2)-based nano/microparticles and coatings were synthesized through a simple, one-step hydrothermal approach without any other additives. Composition, structure, and morphology of the synthesized MoS2-based materials were investigated using ultraviolet-visible spectroscopy (UV-Vis), inductively coupled plasma optical emission spectrometry (ICP-OES), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and energy-dispersive Xray spectroscopy (EDX) techniques. The fabricated materials exhibited relatively small (Delta theta = 18.7 +/- 2.5 degrees) contact angle and prominent hydrophilic properties, which are attributable to sulfur-enriched MoS2 composite as evidenced by simultaneous thermal analysis (STA) coupled with mass spectrometric (MS) analysis of evolving gaseous species (TG/DTA-MS) analysis. Such nanostructures exhibit a better adhesion of biomolecules, thus facilitating the interaction between them, as confirmed by highly effective antimicrobial action. The present study examines antimicrobial properties of hydrophilic, sulfur-enriched MoS2 nano/microparticles as well as MoS2-based coatings against various humans' pathogenic bacteria such as Salmonella enterica, Pseudomonas aeruginosa, Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), Micrococcus luteus, and two Candida yeast strains (C. parapsilosis, C. krusei). The MoS2-ns (40 mu g mL(-1)) showed over 90% killing efficiency against S. aureus MRSA bacteria and both Candida yeast when exposed for 24 h. Petal-like MoS2 microstructures and heterostructured MoS2/Ti and Pd/MoS2/Ti coatings also possessed high antimicrobial potential and are considered as a promising antimicrobial agent. The MoS2-induced production of intracellular reactive oxygen species (ROS) was evidenced by measuring the standard DCF dye fluorescence. (C) 2021 Elsevier Inc. All rights reserved.
Keywords:Molybdenum disulfide (MoS2);Pd nanoparticles;Antimicrobial activity;Reactive oxygen species;Biofuel cells;MoS2/Ti hetero-structures