Bioimaging potential: Comparative study of ZnO nanoparticles synthesized via green and chemical routes

Zinc Oxide Nanoparticles (ZnO NPs) were synthesized through chemical and green synthesis methods employing Ficus religiosa (peepal) leaf extract. The synthesized nanoparticles underwent comprehensive characterization using various techniques such as Powder X-ray Diffractometry (PXRD), Fourier-transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Photoluminescence (PL), UV–visible Spectroscopy, and Spectroscopic Ellipsometry. The PXRD analysis confirmed a hexagonal wurtzite structure with excellent crystallinity in the product. UV–visible studies indicated band gap energies of 3.13 eV and 2.7 eV for green-synthesized and chemically synthesized ZnO NPs, respectively. There was notable augmentation in the fluorescence characteristics of ZnO NPs derived through green synthesis when compared to chemically synthesized NPs. This observed enhancement in fluorescence renders the green-synthesized ZnO NPs particularly advantageous for bio-imaging. • Green ZnO NPs were synthesized using an aqueous extract of Ficus religiosa leaves. • In the 300–380 nm UV range, Green ZnO NPs shows significantly high absorbance. • Augmented fluorescence of Green ZnO NPs makes it ideal for bio-imaging applications.