Extract-dependent biosynthesis and characterisation of zinc oxide nanoparticles derived from Bacopa monnieri (L.)
摘要
A cost-effective and environmentally sustainable approach was employed to fabricate zinc oxide nanoparticles (ZnONPs) using aqueous, ethanolic, and methanolic extracts of Bacopa monnieri (L.). ZnONPs are gaining increasing importance and are widely explored by many researchers due to their potential therapeutic applications in anti-inflammatory, antifungal, anti-diabetic, antibacterial, antioxidant, and wound-healing effects. Contrary to traditional chemical and physical synthesis methods that often require harmful reagents as reducing and stabilising agents, this study employs an environmentally friendly approach through plant-mediated green synthesis, utilising phytochemicals as natural reducing and stabilising agents. The synthesis of ZnONPs was validated through UV–Visible spectroscopy, which displayed distinct excitonic absorption peaks within the range of approximately 320–350 nm. The analysis using Transmission Electron Microscopy (TEM) indicated the presence of quasi-spherical nanoparticles, with average particle sizes varying between approximately 16–24 nm, contingent upon the solvent extract utilised. The FTIR spectra displayed significant Zn–O stretching vibrations within the range of approximately 450–550 cm⁻¹, in addition to functional groups linked to phytochemicals that play a crucial role in capping and stabilisation. The confirmation of structural and compositional analyses was achieved through the application of XRD and EDX techniques. This study offers a thorough solvent-based comparative analysis of ZnONPs synthesised from three distinct extracts (aqueous, ethanolic, and methanolic) of Bacopa monnieri (L.), emphasising the variations in particle size, optical properties, and stabilisation behaviour that depend on the extract used, which may have significant implications for future pharmaceutical applications.