Au@Ag Core@Shell Nanoparticles Synthesized with Rumex hymenosepalus as Antimicrobial Agent

Area of Science:

• Nanotechnology
• Materials Science
• Microbiology

Background:

• Green synthesis of nanoparticles offers an eco-friendly alternative to traditional methods.
• Plant extracts rich in phytochemicals like catechins and stilbenes are effective reducing and stabilizing agents.
• Bimetallic nanoparticles exhibit unique properties compared to their monometallic counterparts.

Purpose of the Study:

• To synthesize and characterize gold-silver bimetallic nanoparticles (Au@AgNPs) using Rumex hymenosepalus root extract.
• To investigate the antimicrobial activity of synthesized gold nanoparticles (AuNPs), silver nanoparticles (AgNPs), and Au@AgNPs against Escherichia coli and Candida albicans.

Main Methods:

• Sequential synthesis of Au@AgNPs with a core@shell structure.
• Characterization using TEM, STEM-HAADF, EDS, XRD, UV-Vis, Zeta Potential, DLS, FTIR, and XPS.
• Microbial growth kinetics study using the Gompertz model.

Main Results:

• Au@AgNPs, AuNPs, and AgNPs were synthesized with mean diameters of 36±11 nm, 24±4 nm, and 13±3 nm, respectively.
• The silver shell thickness was approximately 6 nm, and nanoparticles were stabilized by plant biomolecules.
• AgNPs and Au@AgNPs demonstrated a dose-dependent inhibition of E. coli and C. albicans growth, with Au@AgNPs showing superior efficacy.

Conclusions:

• Rumex hymenosepalus extract is an effective green synthesis agent for Au@AgNPs.
• The synthesized Au@AgNPs exhibit significant antimicrobial activity against E. coli and C. albicans.
• Au@AgNPs hold potential for applications requiring antimicrobial properties.