Characterization and Antibacterial Activity of Biosynthesized Zinc Oxide–Silver (ZnO–Ag) Nanocomposites Using Manihot esculenta Leaf Extract

Box-Behnken-Optimized Bacterial Nanocellulose-Silver and Zinc Oxide Nanocomposites: Bactericidal Activity, Antioxidant Capacity, Cytotoxicity, and In vitro Wound Healing Assessment.

Antibacterial activity and characterization of ZnO and Ag-doped ZnO nanoparticles fabricated using Leucophyllum frutescens leaf extract

Globally, there has been considerable interest in the environmentally benign production of transition-metal nanoparticles. This study describes the synthesis of ZnO and Ag-doped ZnO nanoparticles using the leaf extract of Leucophyllum frutescens via a simple green method. The synthesized nanoparticles were characterized by Ultraviolet-Visible (UV-Vis) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM), and scanning electron microscopy (SEM). TEM analysis showed that the crystallites were spherical and polyhedral, highly agglomerated, and had interplanar diameters ranging from 0.2005 to 0.2625 nm. The antimicrobial efficacy of the developed ZnO and Ag/ZnO nanoparticles at concentrations of 3%, 5%, and 7% was evaluated against human pathogens, including Bacillus cereus, Staphylococcus aureus, Salmonella typhi, and Escherichia coli. The synthesized ZnO and Ag-doped ZnO nanoparticles showed a characteristic absorption band in the UV region, confirming successful formation of ZnO-based semiconductor nanostructures and supporting their antibacterial activity against the tested pathogens. The results revealed that at 7% Ag-doping, Ag-doped ZnO nanoparticles exhibited greater antibacterial efficacy than pure ZnO nanoparticles, with the largest inhibition zones observed against S. aureus (11 ± 3.0 mm) and B. cereus (12.45 ± 0.57 mm). Overall, this plant-mediated synthesis of Ag-doped ZnO nanoparticles offers a promising route for developing enhanced antibacterial agents and highlights a green, cost-effective, and sustainable method for producing ZnO and Ag-doped ZnO nanoparticles, with various applications for future exploration.

Biological Activities and Host-Response Insights of Ocimum basilicum Flower-Derived Silver Nanoparticles

Antimicrobial resistance and the limitations of conventional antimicrobial therapies have intensified the search for multifunctional nanoscale agents. Plant flowers are effective and sustainable biological materials for the eco-friendly synthesis of stable nanoparticles. In this study, Ocimum basilicum flower (OBF) extracts were used for the synthesis of silver nanoparticles (OBF-AgNPs) and evaluated for antimicrobial and antibiofilm activities. Characterization by UV–Vis spectroscopy, FTIR, SEM, TEM, EDX, DLS, and zeta-potential analysis revealed an absorption maximum at 440 nm and predominantly spherical particles measuring 5–38 nm. The hydrodynamic diameter was 53.84 nm, with a PDI of 0.4123 and a zeta potential of −23.47 mV. OBF-AgNPs showed greater antimicrobial activity than the crude extract and AgNO3, with MIC and MBC values of 97–194 and 388–776 µg/mL, respectively. Biofilm formation was inhibited against S. aureus, P. aeruginosa, and C. tropicalis in a concentration-dependent manner. Eight GC–MS-identified phytochemicals were separately examined through network pharmacology. Of 124 predicted targets, 34 overlapped with microbial-infection-related genes, and enrichment analysis highlighted inflammatory and immune-response pathways. Molecular docking against the network-derived host-target PTGS2 showed moderate predicted interactions compared with reference inhibitors, with τ-cadinol showing the lowest docking score of −7.7 kcal/mol among the tested phytochemicals. Overall, the synthesized OBF-AgNPs demonstrated antimicrobial and antibiofilm activities. The in silico analyses independently identified host-response-related computational insights from GC–MS-identified flower constituents.

Bioengineered ZnO/Activated Carbon Nanocomposites for Combating Multidrug-resistant Bacterial Strains

Antibacterial and Antibiofilm Potential of Silver Oxide Nanoparticles (Ag2ONPs) Synthesized Using Dioscorea bulbifera Tuber Extract

The present study focuses on the green synthesis of silver oxide nanoparticles (Ag2ONPs) from Dioscorea bulbifera tubers and the assessment of their antibacterial and antibiofilm potential. Aqueous extract of D. bulbifera tubers was mixed with AgNO3 to synthesize Ag2ONPs. Ag2ONPs were characterized by UV–Vis spectroscopy, SEM, XRD, and FTIR. Antibacterial and antibiofilm activities were assessed against Escherichia coli NCIM 2065, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Serratia nematodiphila MT754555, Pectobacterium carotovorum MCC 2112, and Chromobacterium violaceum CV026 using agar well diffusion and crystal violet assay, respectively. Synthesized Ag2ONPs exhibited characteristic brown coloration, which was confirmed by a surface plasmon resonance peak at 433 nm. SEM analysis revealed a particle size range of 13–24 nm, with XRD confirming a crystalline structure and FTIR indicating tuber-derived phytochemicals as capping/stabilizing agents. Ag2ONPs showed significant antibacterial activity and biofilm inhibition at 200–1000 ppm against the tested organisms. The findings showed that the Ag2ONPs were synthesized successfully and maintained their stability through their specific optical characteristics. The study demonstrates the efficient green synthesis of Ag2ONPs, where phytochemicals act as capping agents, stabilizing their crystalline structure and small size. The Ag2ONPs showed antibacterial and antibiofilm abilities, which became more effective at greater concentration levels. Ag2ONPs showed enhanced antibacterial activity, highlighting the impact of combining nanotechnology with biomolecules obtained from plants. These findings emphasize the potential of Ag2ONPs as antibacterial and antibiofilm agents, signifying their importance in the management of infectious diseases.

Development and Characterization of a Sustainable Pectin-Based Zeolite–Zno Hybrid Nanocomposite for Antibacterial Biomedical Applications

A novel nanocomposite comprising pectin, zeolite, and zinc oxide (ZnO) nanoparticles (NPs) was hypothesised to enhance antibacterial activity through synergistic effects. Consequently, the material was investigated as a green antibacterial agent for biomedical applications. Pectin was extracted from green apples using ethanol precipitation and dried at 50°C. The nanocomposite was prepared by mixing 1% (w/v) pectin, 2% (w/v) zeolite, and 0.5% (w/v) ZnO nanoparticles in water, followed by stirring for 2 hours at room temperature. For antibacterial testing, 100 µL of a 10^6 CFU/mL bacterial suspension was spread on Mueller-Hinton agar. Composite discs (6 mm diameter, 20 mg) were placed on the plates. After 24 hours of incubation at 37°C, inhibition zones were measured. Minimum inhibitory concentrations were determined by broth microdilution (10–200 µg/mL) in 96-well plates. FTIR analysis confirmed the presence of functional group interactions within the materials. The pectin-zeolite-ZnO nanocomposite had strong antibacterial activity against both bacteria. For Staphylococcus aureus, the nanocomposite produced an inhibition zone of 18 ± 0.5 mm and for Escherichia coli, 16 ± 0.6 mm. These values were significantly greater than those observed for the pectin (9.3 ± 0.3 mm), zeolite (10.1 ± 0.4 mm), or ZnO nanoparticles alone (13 ± 0.5 mm). The minimum inhibitory concentration (MIC) for the nanocomposite was 40 µg/mL against S. aureus and 50 µg/mL against E. coli. This increase in antibacterial efficacy results from the synergy among zeolite, pectin, and ZnO nanoparticles, which enhances bacterial cell disruption and inhibition. The developed nanocomposite is a promising antibacterial agent. Its strong antibacterial activity suggests potential use in biomedical applications such as wound dressings, implant coatings, or antibacterial surfaces, where effective inhibition of bacterial growth is essential. These results highlight the nanocomposite's translational potential for preventing infections and supporting the development of safe biomedical devices.