Browsing by Author "Kottegoda, N"

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    PublicationOpen Access
    Copper-Based Nanoparticles as Precision Nanoantibiotics against Bacterial Blight in Anthurium andraeanum Lind.: Synthesis, Characterization, and Antibacterial Efficacy under In Vitro and In Vivo Conditions
    (American Chemical Society, 2026-05-05) Wanaguru, S; Jayasinghe, S; Seneviratne, K; Kottegoda, N; Peiris, Sriyani E; Peiris, Colin N
    The bacterial blight disease caused by Xanthomonas spp., a dilemma for farmers worldwide. The existing conventional methods have failed to effectively combat the disease. Therefore, it is crucial to focus on developing and implementing more affordable techniques to effectively manage bacterial blight effectively. Herein, we investigated the efficacy of copper-based nanoparticles (Cu NPs) synthesized via three different methods toward controlling bacterial blight disease in Anthurium andraeanum plants. For that, Cu NPs were engineered via chemical, semichemical, and green synthesis approaches. Cu NPs were characterized through scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier-transform infrared (FTIR), and powder X-ray diffraction (PXRD) analysis. Quantitative antibacterial assays revealed that the chemical and green-synthesized Cu NPs exhibited the highest potency, with a minimum inhibitory concentration (MIC) of 31.25 μg/mL and a minimum bactericidal concentration (MBC) of 62.50 μg/mL, whereas the semichemical formulation showed lower activity (MIC = 62.50 μg/mL; MBC = 125 μg/mL). In vitro well-diffusion assays further supported this trend: at 30 ppm, the inhibition zones measured 25 ± 0.81, 15 ± 0.81, and 20.6 ± 0.94 mm for the chemical, semichemical, and green synthesis methods, respectively, compared to 26.3 ± 0.47 mm for the positive control-antibiotic sulfamethoxazole. At in vivo, optimized concentration of 200 ppm, Cu NPs produced via all three methods controlled bacterial blight disease in 90% of treated anthurium plants within 4, 7, and 5 weeks, respectively, without causing phytotoxicity. Disease progression was monitored over 12 weeks by measuring lesion areas, and statistical significance of treatments was determined using two-way analysis of variance (ANOVA). ©
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    Facile synthesis of silver/iron-TiO2 nanoparticles for sterilization of Nodal explants of Dracaena sanderiana Sander ex Mast. cvs ‘Gold’ and ‘Victory’ and growth regulator effects on in vitro growth
    (OICC Press, 2025-02-08) Seneviratne, K.L; Peiris, S. E.; Peiris, C. N; Shashikala, R. P. A; Jayasinghe, S; Kottegoda, N
    This study investigates the application of silver/iron-titanate (Ag/Fe-TiO2) nanoparticles (NPs) as a sterilizing agent for in vitro cultures of Dracaena sanderiana cultivars ‘Gold’ and ‘Victory’. The motivation behind this research is to find an effective sterilization method that does not harm plant growth. The Ag/Fe-TiO2 NPs, activated by visible light, exhibit catalytic properties that eliminate harmful microbes such as Escherichia coli, Staphylococcus aureus, and Fusarium spp. The main findings indicate that the combination of Benzyl Amino Purine (BAP) at 1.5 mg/L and Indole Acetic Acid (IAA) at 0.01 mg/L significantly enhances shoot number and length in both cultivars. The use of 200 mg/L Ag/Fe-TiO2 NPs achieved 90% contamination-free cultures in the first cycle, with a slight decrease to 80% in the second cycle and 70% in the third cycle. Importantly, the treatment not only sterilizes but also promotes plant growth, suggesting that Ag/Fe-TiO2 NPs could be a sustainable solution for in vitro plant mass production. © 2025 The Author(s)
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    PublicationOpen Access
    Recent progress in visible-light active (VLA) TiO2 nano-structures for enhanced photocatalytic activity (PCA) and antibacterial properties: a review
    (Islamic Azad University, Shahreza Branch, 2021-09-01) Seneviratne, K. L; Munaweera, I; Peiris, S; Peiris, C. N; Kottegoda, N
    The applications of photocatalytic nanomaterial technology received intense scientific focus with the advent of nanotechnology. Applications based on TiO2 nanoparticles have shown promise of photocatalytic efficiency among many semiconductor metal oxides. Titanium dioxide is utilized in many practical applications such as water and air purification, self-cleaning of surfaces, and energy production. The major drawback with TiO2 based photocatalysts is the wide band gap, which requires UV light to produce the electron-hole pairs. This review article focus on techniques/methods to eliminate band gap which reduces photocatalytic efficiency. Application of semiconductor photocatalytic techniques to degrade organic pollutants and their antimicrobial activity is discussed here using model systems. Synthetic and natural nanohybrids are available today and have varying characteristics as options. Recently developed natural mineral based nanohybrids is the new trend in photocatalytic applications. It appears that the removal efficiency of existed photocatalysts is higher than that of synthetic products. Natural nanohybrids carry the advantages of low costs, avoiding extensive synthesizing conditions in future photocatalytic applications.
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    Visible Light Active Silver Decorated Iron Titanate/Titanium Dioxide Nanohybrid for Sterilization of Explants Grown by In Vitro Technique
    (John Wiley and Sons, 2022-12-04) Seneviratne, K .L; Munaweera, I; Peiris, S. E; Kodithuwakku, P; Peiris, C. N; Kottegoda, N
    Visible light (VL) active silver decorated iron titanate/titanium dioxide (Ag-FeTiO3/TiO2) nanohybrids derived from natural ilmenite sand effectively cleanse the exophytic plant pathogens in explants grown by in vitro techniques. VL active nanohybrid is synthesized by acid-hydrolysis of natural ilmenite, followed by precipitation of the lixivium and decoration with Ag onto FeTiO3/TiO2 nanoparticles, and finally calcination under a nitrogen environment to obtain Ag-FeTiO3/TiO2. A morphological study conducted using transmission electron microscopy (TEM) confirms the formation of Ag-FeTiO3/TiO2. Powder X-ray diffraction (PXRD) analysis shows that the nanohybrid primarily consists of anatase, iron titanate (FeTiO3), Ag2O, and Ag. X-ray photoelectron spectroscopy (XPS) study suggests the presence of Ag0/Ag2O/Fe2O3 composites on the FeTiO3/TiO2 particle surface. The optical band gap significantly changes from 3.14 eV (ilmenite) to 2.80 eV after the decoration of FeTiO3/TiO2 with Ag. This nanohybrid is utilized as a surface-sterilizing agent for in vitro establishment of the Dracaena sanderiana Sander ex Mast plant. Findings illustrate Ag-FeTiO3/TiO2 nanohybrid-based photo-sterilization leads to the survival of 90% of the microbes’ free cultures while the material can be re-used due to its photocatalytic behavior. Thus, the newly synthesized nanohybrid can replace harmful sterilization agents used in tissue culture techniques