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This study explores a novel, eco-friendly approach to silver nanoparticle (AgNP) synthesis by using rose petal (RP) extracts. Unlike traditional chemical synthesis, this method reduces silver ions (Ag+) to elemental silver (Ag0) with RP, facilitating nanoparticle stabilization. RP-AgNPs were structurally characterized using UV/Vis (ultraviolet/visible) spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering, zeta potential, transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy which confirmed the synthesis of predominantly spherical to oval RP-AgNPs, with a distinct absorption peak at 410 nm as observed in UV/Vis spectra. The NPs demonstrated exceptional antibacterial efficacy against Escherichia coli and Staphylococcus aureus (inhibitory zones of 12.5 ± 0.20 and 14 ± 0.67 mm at 50 µg) and potent antibiofilm activity. Crucially, they also exhibited selective cytotoxicity toward HeLa cervical cancer cells when assessed by viability assays, fluorescence imaging, and flow cytometry. These findings underscore the potential of green synthesized AgNPs for future biomedical applications in areas such as infection control and cancer treatment.

Copper oxide nanoparticles (CuO NPs) were synthesized using ayurvedic medicine septilin. The septilin-mediated CuO NPs were characterized using UV–Vis, fourier-transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). The average particle size of CuO NPs was 8 nm as evident from TEM. Minimum inhibitory concentration of CuO NPs against Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans was found in the range of 1–2.5 mg·mL−1. CuO NPs dose-dependently decreased the biofilm formation from 0.0315 to 2 mg·mL−1, at the highest dose of 2 mg·mL−1 of CuO NPs; 92.91%, 79.84%, and 71.57% decrease in biofilm was observed for P. aeruginosa, MRSA, and C. albicans, respectively. Down-regulation of biofilm upon treatment with nanoparticles (NPs) was also observed by SEM analysis. SEM analysis also showed the change in morphological structure, and deformities in bacterial and fungal cells upon treatment of NPs. Furthermore, the anticancer efficacy of NPs was assessed using colon cancer (HCT-116). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay clearly showed the anticancer potential of NPs, as the concentration of CuO NPs increased, the number of viable cells decreased. The produced CuO NPs have promise for future investigations in many biological and therapeutic domains, including the treatment of microbial biofilm infections, as well as the inhibition of cancer cell growth.

The primary goal of this work was to develop a cost-effective, non-toxic, eco-friendly, and simple approach for the green synthesis of CoFe2O4 nanoparticles (NPs) using Aloe vera leaf extract by the sol–gel auto-combustion method. In order to figure out their structural, morphological, and magnetic properties, the synthesized NPs were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), dynamic light scattering (DLS), zeta potential, and vibrating-sample magnetometer (VSM). XRD analysis showed that particles had a single-phase spinel crystalline structure with an average crystalline size of 33.5 nm. Under VSM studies, the produced NPs exhibit a soft ferromagnetic property. SEM revealed that the as-prepared NPs were agglomerated due to their magnetic behavior. To the best of our knowledge, the anticandidal, antibiofilm, antibacterial, and anticancer activities of CoFe2O4 NPs toward drug-resistant gram-positive and gram-negative bacteria, as well as fungal strains, have been comprehensively investigated for the first time. The synthesized NPs had a minimal inhibitory concentration of 0.25–0.75 mg/ml against the tested pathogens. CoFe2O4 NPs inhibited the biofilm formation by 37.3–61.8% in selected strains at concentrations of 0.125–0.5 mg/ml. It was observed that the NPs not only suppress biofilm formation but also eradicate established mature biofilms by 50.9–64.49% that was further supported by SEM. SEM analysis shows that NPs significantly inhibit the colonization and aggregation of tested biofilm strains. Light microscopic analysis revealed that NPs completely inhibit the development of hyphae and filaments in Candida albicans, which significantly attenuates their pathogenicity. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and 4′,6-diamidino-2-phenylindole (DAPI) staining demonstrate that NPs significantly inhibit the proliferation of HCT-116 and HeLa cells. Furthermore, the SEM images of treated cells showed wrinkled and damaged cell walls, indicating the disruption and disorganization of the membrane. This study showed that the synthesized NPs were effective in inhibiting the growth of drug-resistant bacteria, candida, and their preformed biofilms as well. Thus, these NPs with broad-spectrum applications could be exploited in medical settings to diminish biofilm-based infections caused by these pathogenic strains.

Nickel(ii) oxide-graphitic carbon nitride (n-NiO@g-C3N4) nanocomposite, in which nickel oxide nanoparticles (n-NiO) are anchored on the polymeric surface of graphitic carbon nitride (g-C3N4), was synthesized using the pulsed laser post processing (PLPP) in liquid medium. In the PLPP method, the precursors (NiO and g-C3N4) were simultaneously subjected to pulsed laser-induced fragmentation, and pulsed laser-induced defect engineering (anchoring of NiO on g-C3N4). To optimize the functionality of the material, n-NiO@g-C3N4 with four different mass contents of n-NiO was synthesized. The synthesized n-NiO@g-C3N4 nanocomposite and its composite partners (n-NiO and g-C3N4) were structurally, morphologically, elementally characterized by X-ray diffraction, filed emission scanning electron microscope, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analyses. As a first anti-microbial application, n-NiO@g-C3N4 was used to evaluate the minimal inhibitory concentration and minimal bactericidal concentration against the gram-positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa bacteria. As a second anti-microbial application, the efficacy of n-NiO@g-C3N4 nanocomposite to retard S. aureus and P. aeruginosa biofilms’ growth was evaluated. It was found that for both applications, n-NiO@g-C3N4 nanocomposite exhibited an excellent anti-bacterial activity compared to pure g-C3N4.