Green Synthesis of Silver Nanoparticles Using an Otherwise Worthless Weed Mimosa (Mimosa pudica): Feasibility and Process Development Toward Shape/Size Control

Abstract

A bioinspired method of silver nanoparticle (AgNP) synthesis using the highly invasive terrestrial weed mimosa (Mimosa pudica) is presented. An aqueous extract of the leaves of the weed that served as a reducing and stabiliaing agent was employed in various proportions with Ag (I) solution for this synthesis. The effect of several key variables that influence the shape/size of the AgNPs—concentrations of the extract relative to Ag (I), temperature, interaction time, stirring, and pH—was studied employing UV-visible spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and x-ray diffraction (XRD). The study provides the basis for selecting processes for synthesizing AgNPs of desired shapes and sizes that can be developed using mimosa as the bioagent. All processes in this synthesis, being simple, nonpolluting, inexpensive, and nonhazardous, raise the possibility of large-scale utilization of mimosa, thereby offering a means to reduce ecological degradation that is caused by mimosa.

Keywords:

• biomimetic synthesis
• Mimosa pudica
• silver nanoparticles
• surface plasmon resonance

Acknowledgments

The authors thank the Central Instrumentation Facility and similar units of Pondicherry University, IIT Madras, and North–Eastern Hill University for providing access to the various sophisticated instruments used in this study.