Novel polyherbal-mediated ZnFe₂O₄ nanoparticles: Synthesis, characterization, antimicrobial, and anti-inflammatory evaluation against respiratory pathogens.

This study was to explore a green chemistry approach to the biomimetic fabrication of zinc ferrite nanoparticles (ZnFe₂O₄ NPs) using a polyherbal formulation of Nigella sativa, Trachyspermum ammi, and Trigonella foenum-graecum seed extracts to replace non-biodegradable synthetic chemicals. The structural, optical, morphological as well as functional properties of nanoferrites have been characterized. Powder X-ray Diffraction (PXRD) analysis reveals the highly crystalline nanophase of ZnFe₂O₄ NPs. FTIR spectroscopy identified active phytochemicals along with the characteristic metal‑oxygen bands and UV-Vis Diffuse Reflectance Spectroscopy revealed a semiconducting band gap of 4.2 eV. The SEM image shows the formation of agglomerated nanoplates, and EDS spectra confirm the nanoferrites elemental composition. The biosynthesised nanoparticles have exhibited significant antimicrobial activity against Gram (+), Gram(-) bacterial and fungal pathogens. The anti-inflammatory efficacy of biosynthesised nanoferrites was assessed by protein denaturation and membrane stabilizing activity assays. The synthesised ZnFe₂O₄ NPs possess multi-functional bioactivity that has antimicrobial and anti-inflammatory activities. Hence, they are promising candidates for biomedical applications against Lower Respiratory Tract Infections (LRTIs).