Mechanistic insight into the endophytic fungus mediated synthesis of protein capped ZnO nanoparticles

Abstract

Present investigation is focused on the development of environment friendly protocol for ZnO nanoparticles synthesis using mycelial free filtrate of unexplored endophytic fungus Cochliobolus geniculatus. Zinc metal tolerant endophyte was isolated from leaves of Nothapodytes foetida and identified based on rDNA internal transcribed spacer region sequence. Surface plasmon resonance examined by UV–VIS spectroscopy analysis confirmed the synthesis of ZnO nanoparticles; exhibiting a band gap of 3.28 eV. The obtained nanoparticles were characterized by energy dispersive X-ray (EDX), high resolution transmission electron microscopy and XRD analysis. The synthesized ZnO nanoparticles were found to be polydispersed and well distributed deprived of agglomeration, crystalline, quasi spherical particles exhibiting a narrow range distribution. Fluorescence, FTIR and UV–VIS spectra depicted presence of extracellular proteins which was further confirmed by SDS-PAGE study that displayed occurrence of 52 kDa and 58 kDa protein bands involved in the synthesis of ZnO nanoparticles and further act as capping material. © 2019 Elsevier B.V.