Phytosynthesis of silver nanoparticles from aqueous leaf extracts of Piper colubrinum: characterisation and catalytic activity

Abstract In bionanotechnology, nanoparticles synthesis using biological samples is a broadly used technique as it confers lesser toxicity than chemical methods. Leaf extract of Piper colubrinum Link. was used to synthesise green mediated silver nanoparticles (AgNPs). The confirmation and stability of green synthesised silver nanoparticles by UV–visible spectroscopy showed an absorption peak at 410 nm. The synthesised nanoparticles characterised by Fourier transformed infra-red spectroscopy exhibited possible involvement of various functional groups and bio capping of AgNPs and the crystal structure was confirmed by X-ray diffraction data. Further, the size of synthesised silver nanoparticles was confirmed using transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and atomic force electron microscopy. The spectroscopic and microscopic analysis confirmed the successful synthesis of AgNPs by P. colubrinum extracts acting as strong reducing agents. Our results showed that reducing the silver nitrate with plant extracts formed sphere-shaped AgNPs with distances in the range of 10–50 nm. XRD analysis revealed the crystal-like nature of the nanoparticles with face-centred cubic structure, and the peaks of the XRD pattern were parallel to (111), (200), (220), and (311) planes. The synthesised AgNPs showed the potential antibacterial activity against foodborne pathogens Escherichia coli and Staphylococcus aureus. Spectrophotometric analysis of dye degradation was confirmed the catalytic activity of synthesised AgNPs. The results of the study revealed potential of phyto-synthesised AgNPs act as catalysts and is a simple and cost effective and efficient approach.