Biogenic synthesis of Ag, Au and bimetallic Au/Ag alloy nanoparticles using aqueous extract of mahogany (Swietenia mahogani JACQ.) leaves

In this paper, we have demonstrated for the first time, the superb efficiency of aqueous extract of dried leaves of mahogany (Swietenia mahogani JACQ.) in the rapid synthesis of stable monometallic Au and Ag nanoparticles and also Au/Ag bimetallic alloy nanoparticles having spectacular morphologies. Our method was clean, nontoxic and environment friendly. When exposed to aqueous mahogany leaf extract, competitive reduction of AuIII and AgI ions present simultaneously in same solution leads to the production of bimetallic Au/Ag alloy nanoparticles. UV–visible spectroscopy was used to monitor the kinetics of nanoparticles formation. UV–visible spectroscopic data and TEM images revealed the formation of bimetallic Au/Ag alloy nanoparticles. Mahogany leaf extract contains various polyhydroxy limonoids which are responsible for the reduction of AuIII and AgI ions leading to the formation and stabilization of Au and Ag nanopaticles.

Aqueous extract mahogany (Swietenia mahogani JACQ.) leaves, rich in polyhydroxy limonoids is responsible for the reduction of AuIII and AgI ions leading to the formation and stabilization of monometallic Ag (a) and Au (b) and also bimetallic Au/Ag alloy (c) nanoparticles having spectacular morphologies.Figure optionsDownload as PowerPoint slideResearch highlights▶ Aqueous extract mahogany (Swietenia mahogani JACQ.) leaves, rich in polyhydroxy limonoids is responsible for the reduction of AuIII and AgI ions leading to the formation and stabilization of monometallic Ag and Au and also bimetallic Au/Ag alloy nanoparticles having spectacular morphologies. ▶ Our method is environmentally benign, hazard free and low cost. ▶ Single naturally occurring plant based biogenic material is acting as the reducing agent as well as stabilizing agent. We did not use any synthetic stabilizing agents e.g. surfactants or synthetic polymers.