Phyto-assisted synthesis of bio-functionalised silver nanoparticles and their potential anti-oxidant, anti-microbial and wound healing activities

Abstract

Bio- synthesis of silver nanoparticles (AgNPs) was made by using the aqueous leaf extract of Ardisia solanacea. Rapid formation of AgNPs was observed from silver nitrate upon treatment with the aqueous extract of A. solanacea leaf. The formation and stability of the AgNPs in the colloidal solution were monitored by UV-visible spectrophotometer. The mean particle diameter of AgNPs was calculated from the DLS with an average size ∼4 nm and ∼65 nm. ATR-FTIR spectroscopy confirmed the presence of alcohols, aldehydes, flavonoids, phenols and nitro compounds in the leaf which act as the stabilizing agent. Antimicrobial activity of the synthesized AgNPs was performed using agar well diffusion and broth dilution method against the Gram-positive and Gram-negative bacteria. Further, robust anti-oxidative potential was evaluated by DPPH assay. The highest antimicrobial activity of synthesized AgNPs was found against Pseudomonas aeruginosa (28.2 ± 0.52 mm) whereas moderate activity was found against Bacillus subtilis (16.1 ± 0.76), Candida kruseii (13.0 ± 1.0), and Trichophyton mentagrophytes (12.6 ± 1.52). Moreover, the potential wound healing activity was observed against the BJ-5Ta normal fibroblast cell line. Current research revealed that A. solanacea was found to be a suitable source for the green synthesis of silver nanoparticles.

Fig. 1

UV–Vis spectra of AgNPs synthesised by A. solanacea leaf extracts

Fig. 2

DLS spectra on hydrodynamic size distribution of synthesised AgNPs (a) The x‐axis and y‐axis represent size (nm) and intensity (%); respectively; (b) The characteristic response of zeta potential (mV)

Fig. 3

XRD diffractogram of the bio synthesised silver nanoparticles from the plant extracts of A. solanacea

Fig. 4

Scanning electron microscopy image of biosynthesised silver nanoparticles

Fig. 5

HR‐TEM image of biosynthesised silver nanoparticles

Fig. 6

FTIR result analysis of AgNPs synthesised by A. solanacea leaf. The x‐axis represents spectra (cm⁻¹) and y‐axis represents transmission (%)

Fig. 7

Total TPC and TFC content of A. solanacea

Fig. 8

DPPH radical scavenging assay aqueous extract of A. Solanacea

Fig. 9

Anti‐microbial activity of AgNPs synthesised by A. solanacea against (a) B. subtilis, (b) P. aeruginosa, (c) T. mentagrophytes

Fig. 10

(a) BJ5‐Ta cells treated with leaf extract, (b) BJ5‐Ta cells treated with silver nanoparticles, (c) BJ‐5Ta cells treated with Allantoin (+ve control), (d) BJ‐5Ta cells treated with HBSS (−ve control)