Novel CTAB-Assisted Synthesis of MgO Nanoparticles from Piper longum Leaves: Structural Insights and Hirshfeld Surface Analysis with Bioactivity Evaluation.

This study reports, for the first time, the bio-synthesis of Magnesium Oxide Nanoparticles using Piper longum leaf extract. A sustainable approach was introduced for the fabrication of pure MgO Nanoparticles from the extract of Piper longum leaves through the surfactant Cetyltri methyl ammonium bromide mediated co-precipitation technique. Bioactive phyto chemical compounds in the extract served as a reducing and stabilizing agent, while they act as a surfactant to control the shape and dispersion of nanoparticles. X-ray diffraction confirmed the formation of cubic-phase crystalline magnesium oxide nanoparticles with an average crystallite size of 24.78 nm. The Fourier transform infrared spectra indicated characteristic phyto chemical capping along with Mg-O bonding functional groups stretching around 500 cm⁻¹. Scanning electron microscopy images reveals densely packed porous surface with agglomerated nano clusters, and energy dispersive X-ray spectroscopy confirmed the elemental composition of synthesized nanoparticles and their purity. Hirshfeld surface analysis was performed to analyse the intermolecular interactions as well as surface characteristics of MgO nanoparticles at an atomic level, with emphasis on the significance of strong ionic and hydrogen bonding to their stability. Antibacterial activity was investigated against Escherichia coli and Staphylococcus aureus using the agar well disc diffusion method, showing concentration-dependent with a maximum zone of 14.1 mm observed against Escherichia coli. The synthesised nanoparticles showed great antioxidant activity and these findings report the feasibility of Piper longum-mediated green synthesis of MgO nanoparticles for potential biomedical applications.