Biogenic Silver and Zinc Enhanced MWCNTs: Nano-Decoration, Characterization, and Antimicrobial Effect

In this study, acid-treated multi-walled carbon nanotubes (MWCNTs) were decorated with silver (Ag), zinc (Zn), and Ag@Zn nanoparticles (NPs) synthesized using plant extract for reducing and stabilizing NPs. The nanocomposites were characterized by Scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDX), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and Thermogravimetric analysis (TGA). The stability of functionalized MWCNTs (f-MWCNTs) and NP-decorated MWCNTs was visually evaluated for seven days in ethanol. The antimicrobial efficacy against Gram-positive (Staphylococcus aureus), Gram-negative (Pseudomonas aeruginosa, Escherichia coli) bacteria, and fungi (Candida albicans) was determined using the agar well diffusion assay. Results indicated that Ag-MWCNTs and Ag@Zn-MWCNTs nanocomposites exhibited superior antimicrobial activity against P. aeruginosa and C. albicans compared to other tested microorganisms. Conversely, f-MWCNTs and Zn-MWCNTs showed no antimicrobial effects.