Eco-friendly Synthesis of Silver Nanoparticles Using Carica Papaya Leaf Extract and Its Antibiogram Activity

Abstract

The present study reports an eco-friendlier, cost efficient, rapid and easy method for synthesis of silver nanoparticles using Carica papaya plant leaf extract which act as reducing and capping agent. In this study different factor which affects the silver reduction were investigated. The optimum conditions obtained were for synthesis process were silver nitrate (1mM), plant extract (10ml), pH (4) and incubation time (72 h). Plant extract reduces silver ions into silver nanoparticles within 5 min after heating the reaction mixture (30-80°C) as indicated by the developed reddish brown colour. The UV-vis spectrum of silver nanoparticles revealed a characteristic surface plasmon resonance (SPR) peak at 400-450 nm. Fourier transform infrared spectroscopy affirmed the role of plant extract as a reducing and capping agent of silver ions. Scanning electron microscope and field emission scanning electron microscope showed roughly spherical shaped nanoparticles. The average size of nanoparticles was found to be 80 nm as determined by dynamic light scattering. Energy dispersive X-ray spectroscopy analysis showed the peak in silver region confirming presence of elemental silver. Silver nanoparticles showed effective antibacterial activity against representative pathogens of bacteria. The minimum inhibitory concentration and minimum bactericidal concentration were determined.