Silver nanoparticle synthesis from carica papaya and virtual screening for anti-dengue activity using molecular docking

Silver nanoparticles were synthesized in an aqueous solution of silver nitrate using Carica papaya leaf extract as the reducing agent. These nanoparticles were characterized by photoluminescence and UV–Vis spectroscopy. Fourier-transform infrared spectroscopy results showed that the nanoparticles were capped with biomoites that are responsible for efficient stabilization. XRD analysis revealed that most nanoparticles were spherical in shape with a face-centered cubic structure and crystalline grains. Moreover, Atomic Force Microscopy (AFM) showed that the grain size ranged from 7 to 32 nm, which agreed with the XRD results. The calculated zeta potential was found to be −15.58 mV, which indicated good stability. The antibacterial activity results showed that the synthesized silver nanoparticles exhibited excellent activity against Pseudomonas aeruginosa and Klebsiella pneumoniae. The molecular docking study revealed that the antiviral activity of the C. papaya leaf extract showed good binding affinity against dengue type 2 virus non-structural protein 1. (paper)