Physicochemical characterization of undoped and Fe doped ZnO NPs. [(a),(b)] Matching crystal structure with HRTEM image for undoped and Fe doped ZnO. No detectable structural deviation observed [(c),(d)] d-orbitals splitting of Zn2+ and Fe2+ [(e)–(g)] Induction of OH-1 expression and Jun kinase activation by immuno-blotting and TNF-activation of ZnO, CeO2 or TiO2 (h)–(j) Time dependent toxicity evaluation. Animals were euthanized and BAL fluid was collected to determine PMN numbers, LDH, and albumin levels (supplementary section).18,19