Paper Details

Abstract

This study reports the synthesis of zinc oxide (ZnO) nanoparticles using a plant-based green route and a conventional wet-chemical precipitation route. In the green process, leaf extract of Azadirachta indica served as a natural reducing and stabilizing agent, whereas the wet-chemical route followed a standard base-precipitation protocol. Nanoparticles obtained via the green route showed relatively uniform morphology with an average size of about 5 nm, while particles generated by the wet-chemical method were more compact, with a mean diameter of 2.64 nm. The materials were characterized by UV-Vis (UV–visible (UV–Vis) spectroscopy), AFM (atomic force microscopy) and FTIR (Fourier transform infrared spectroscopy). TGA (thermogravimetric analysis) and DSC (Differential scanning calorimetry) were used to determine the thermal stability, confirming that both nanoparticle systems preserved their structural integrity at elevated temperatures. Antibacterial testing showed the effects of nanoparticles against both gram-positive and gram-negative bacteria. Notably, green-synthesized ZnO nanoparticles exhibited stronger antibacterial performance against Staphylococcus epidermidis, Bacillus subtilis, and Shigella dysenteriae, with a MIC (minimum inhibitory concentration) of 25 µg/mL compared with 125 µg/mL for the wet-chemically prepared sample. Overall, the work demonstrates that plant-assisted synthesis is a sustainable and environmentally friendly alternative that can enhance the biological activity of ZnO nanoparticles. At an inoculum of 10^5 CFU/mL, MIC values for green- and wet-synthesized ZnO nanoparticles (5 and 2.64 nm, respectively) were in the range 0–17 µg/mL. Keywords: Azadirachta indica, antibacterial, AFM, nanoparticle, FTIR.

To Cite This Article