Green synthesis of silver nanoparticles from Aloe vera leaf extract and its antimicrobial activity

Abstract Extensive use of nanoparticles attracted an increased interest in sustainable strategies for its synthesis; which can possibly offer additional advantages. Green synthesis from plant source can offer a clean protocol with many additional qualities contributed by the phytocomponents involved in capping of nanoparticles. In this study, we employed the green synthesis of silver nanoparticles (AgNPs) using the inner gel extract of Aloe vera leaf. Characterisation of the green synthesised AgNPs were done from the spectral analysis of UV–Visible spectrophotometer and Fourier transform infrared spectrometer. Visible observation of colour change and UV–Visible absorption spectrum with plasmon peak at 400 nm confirmed the formation of AgNPs. The FTIR spectra suggested the role of the functional groups in acemannan, the major bioactive polysaccharide of Aloe vera gel, in the formation of AgNPs by acting as a reducing and stabilizing agent. The disc diffusion study indicated an increased antimicrobial activity for green synthesised AgNPs against gram positive Staphylococcus aureus and gram negative Escherichia coli, Pseudomonas aeruginosa and Enterobacter sps. This synergic effect of AgNPs and phytocomponents involved in its capping against the microbes indicates the influence of particle parameters like capping components on the activity of AgNP. These observations open up new possibilities for exploiting Aloe vera gel extract mediated AgNPs in many biomedical applications.