Biosynthesis of silver nanoparticles using Cynara scolymus, Lavandula angustifolia, Alkanna Tinctoria and its antimicrobial activities—A comparative study

Abstract

Nanotechnology is a promising field of science and involves use of nanoparticle with size ranging between 1 nm–100 nm. The phenomenal size properties enable nanoparticles to anchor a prominent place in various biomedical applications. Silver is known for its antimicrobial nature. This study elucidates the qualitative phytochemical properties of three plant extracts, its biogenic synthesis of silver nanoparticles and their antimicrobial activity.  Green Silver nanoparticles (AgNPs) were synthesized from 1mM Silver Nitrate (AgNO₃) solution using leaf extracts of Cynara scolymus (Artichoke), Alkanna tinctoria (Alkanet), and Lavandula angustifolia (Lavender) respectively. The synthesized silver nanoparticles were characterized visually, via UV–vis spectrophotometer and X-ray Diffraction (XRD). The biogenic particles were tested against pathogenic bacterial strains (Staphylococcus aureus, and Escherichia coli) and Plant pathogenic fungal strains (Aspergillus flavus and Aspergillus niger). The formation of AgNPs with size <100 nm was ensured by UV vis spectrophotometer and XRD. Antibacterial activity of lavender mediated AgNP was highly significant, followed by artichoke mediated AgNP and finally, alkanet AgNP were effective. However, in contrast, Artichoke mediated AgNP showed significant activity against plant fungal strains, followed by Alkanet AgNP, and finally by Lavender mediated AgNPs. We concluded that the three plants have versatile biochemical molecules responsible for broad spectrum of AgNP against bacterial and fungal strains. Studies on combined use of AgNPs with other antimicrobial agents may solve the problem of toxicity and possible risk of drug resistance.