Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Synthesis and Antibacterial Evaluation of Silver-Coated Magnetic Iron Oxide/Activated Carbon Nanoparticles Derived from Hibiscus esculentus
Title: Synthesis and Antibacterial Evaluation of Silver-Coated Magnetic Iron Oxide/Activated Carbon Nanoparticles Derived from Hibiscus esculentus
The increasing prevalence of antimicrobial resistance alongside the pharmacological limitations and adverse effects associated with conventional antibiotics necessitates the development of novel and efficacious antimicrobial agents. In this study, magnetic iron oxide nanoparticles (MIONPs) were synthesized via a chemical co-precipitation method. Activated carbon (AC) derived from Hibiscus esculentus (HE) fruit was coated onto the nanoparticle surfaces to fabricate MIONPs/HEAC nanocomposites. To augment their antimicrobial properties, silver ions were chemically reduced and deposited onto the MIONPs/HEAC surface, yielding MIONPs/HEAC@Ag nanocomposites. Comprehensive characterization of the synthesized nanocomposites was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), dynamic light scattering (DLS), and zeta potential analysis. DLS measurements indicated average particle sizes of approximately 122 nm and 164 nm for MIONPs/HEAC and MIONPs/HEAC@Ag, respectively. Saturation magnetization values were determined to be 73.6 emu/g for MIONPs and 65.5 emu/g for MIONPs/HEAC. Antibacterial assays demonstrated that MIONPs/HEAC@Ag exhibited significant inhibitory effects against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923, with inhibition zone diameters of 11.50 mm and 13.00 mm, respectively. In contrast, uncoated MIONPs/HEAC showed negligible antibacterial activity against both bacterial strains. These findings indicate that MIONPs/HEAC@Ag nanocomposites possess considerable potential as antimicrobial agents for biomedical applications, particularly in addressing infections caused by antibiotic-resistant bacteria.  more » « less
Award ID(s):
2422672
PAR ID:
10693137
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
MDPI
Date Published:
Journal Name:
Magnetochemistry
Volume:
11
Issue:
7
ISSN:
2312-7481
Page Range / eLocation ID:
53
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; (, SN Applied Sciences)
    null (Ed.)
    Abstract This paper presents research results of biocidal effect of thermoplastic- polyester-elastomer (TPE-E) with incorporation of hybrid Ag/ZnO/SiO 2 NPs (silver/Zinc oxide/SiO 2 nanoparticles). These results were compared with various gamma-irradiated doses and processing techniques including extrusion, injection molding and compression molding. In all these processing techniques the TPE-E was mixed with mineral oil and Ag/ZnO/SiO 2 nanoparticles. The TPE-E nanocomposites were characterized by differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), Infrared FT spectroscopy (FTIR), surface enhanced Raman technique ( SERS), FESEM (Field emission scanning electron microscopy), Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), TEM (transmission electronic microscopy) and antimicrobial test. Antibacterial activity against E. coli and S. aureus , are reported and these results showed potential application in health care products. 
    more » « less
  2. ; ; ; (, Applied Sciences)
    Graphene and graphene oxide have shown good antibacterial activity against different bacterial species due to their unique physicochemical properties. Graphene oxide (GO) has been widely used to load metallic and metal oxide nanoparticles (NPs) to minimize their surface energy during processing and preparation, hence reducing their aggregation. In this work, GO was effectively synthesized and coated with different concentrations of zinc hydroxide Zn (OH)x using the precipitation method to prepare a GO/Zn (OH)x hybrid composite. The Zn (OH)x NPs and GO/Zn (OH)x nanocomposites were synthesized and characterized using various methods such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Coating GO with Zn (OH)x NPs resulted in improved aggregation of Zn (OH)x NPs as well as enhanced antibacterial activity of GO against Gram-positive and Gram-negative bacteria. Additionally, the effect of Zn (OH)x coating on the antibacterial properties of the GO/Zn (OH)x composite was systematically investigated. The synergistic effects of GO and Zn (OH)x NPs resulted in enhanced antibacterial properties of the composites compared to the pristine GO material. In addition, increasing the Zn (OH)x wt. % concentration led to an increased inhibition zone of the GO/Zn (H)x composite against Bacillus megaterium and E. coli bacteria. 
    more » « less
  3. ; ; ; ; ; ; ; ; ; ; et al (, Nanomaterials)
    This article belongs to the Special Issue Synthesis and Applications of Gold Nanoparticles) Rodolphe Antoine (Ed.)
    This research focuses on the plant-mediated green synthesis process to produce gold nanoparticles (Au NPs) using upland cress (Barbarea verna), as various biomolecules within the upland cress act as both reducing and capping agents. The synthesized gold nanoparticles were thoroughly characterized using UV-vis spectroscopy, surface charge (zeta potential) analysis, scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and X-ray diffraction (XRD). The results indicated the synthesized Au NPs are spherical and well-dispersed with an average diameter ~11 nm and a characteristic absorbance peak at ~529 nm. EDX results showed an 11.13% gold content. Colloidal Au NP stability was confirmed with a zeta potential (ζ) value of −36.8 mV. X-ray diffraction analysis verified the production of crystalline face-centered cubic gold. Moreover, the antimicrobial activity of the Au NPs was evaluated using Gram-negative Escherichiacoli and Gram-positive Bacillus megaterium. Results demonstrated concentration-dependent antimicrobial properties. Lastly, applications of the Au NPs in catalysis and biomedicine were evaluated. The catalytic activity of Au NPs was demonstrated through the conversion of 4-nitrophenol to 4-aminophenol which followed first-order kinetics. Cellular uptake and cytotoxicity were evaluated using both BMSCs (stem) and HeLa (cancer) cells and the results were cell type dependent. The synthesized Au NPs show great potential for various applications such as catalysis, pharmaceutics, and biomedicine. 
    more » « less
  4. ; ; ; ; ; ; (, Biointerphases)
    The growing threat of antibiotic-resistant bacteria necessitates the development of alternative antimicrobial agents. Gallium oxyhydroxide (GaOOH) is a promising candidate, though its direct antibacterial efficacy is unexplored. This study provides the first direct evidence of GaOOH microparticles exhibiting cytotoxic effects against both Gram-positive Staphylococcus aureus (S.aureus) and Gram-negative Escherichia coli (E. coli). Orthorhombic GaOOH particles were synthesized hydrothermally, with their morphology influenced by the pH of the synthesis process, as confirmed by scanning electron microscopy and x-ray diffraction analysis. Antibacterial assays revealed that cytotoxicity against E. coli increases with a higher synthesis pH, a trend we demonstrate to be associated with the enhanced defect density in particles, as supported by photoluminescence spectra and FTIR analysis. The study underscores the significant influence of synthesis conditions on the morphology and crystallinity of the resulting GaOOH microparticles, highlighting the influence of surface characteristics on antibacterial agents. 
    more » « less
  5. ; ; ; ; (, AIP Advances)
    Bismuth ferrite (BiFeO 3 ) nanocomposites were synthesized using a novel nano-agitator bead milling method followed by calcination. Bismuth oxide and iron oxide nanoparticles were mixed in a stoichiometric ratio and milled for 3 h and calcined at 650 °C in air. X-ray diffraction with Rietveld refinement, scanning electron microscopy, and transmission electron microscopy techniques were used to elucidate the structure of BiFeO 3 . The particle diameter was found to be ∼17 nm. Magnetic and electrical measurements were performed, and these results were compared with those of similar methods. Mostly, BiFeO 3 was obtained with minor secondary phase formation. The resulting powder was weakly ferromagnetic with a remnant magnetization of 0.078 emu/g. This can be attributed to residual strain and defects introduced during the milling process. Electrical testing revealed a high leakage current density that is typical of undoped bismuth ferrite. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Text Encoded Conversion
  • XML
  • Save / Share this Record
  • Send to Email