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

Abstract

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). ©