Sustainable Green Synthesis of Leaf Extract-Stabilized Silver Nanoparticles: Catalytic, Antimicrobial Properties and Colorimetric Sensing of Hg2+

Green synthesis of silver nanoparticle(Ag NPs) s employing the aqueous extract of three different dried leaves, Murraya koenigi, Ocimum sanctum and Mentha spicata leaves was carried out. Different techniques, including UV-Visible spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to characterize green synthesized silver nanoparticles. The AgNPs are found to have effective catalytic properties in the reduction of 4-nitrophenol and in the degradation of methyl orange and methylene blue dyes. Mercuric ion was selectively detected at ppm level with the green silver nanoparticles. Their antibacterial efficacy was evaluated against both Gram-negative Pseudomonas fluorescens and Gram-positive Bacillus megaterium bacteria. This study also explores the antifungal properties of green synthesized silver nanoparticles with Candida albicans and Candida parapsilosis.