title: Bio-inspired morphological evolution of zinc oxide nanostructures on a tunable enzyme platform.
abstract: Diamine oxidase is a copper-containing enzyme with interesting structural dynamics sensitive to environmental conditions. The present work explores the applicability of the system as a tunable platform for the shape and size selective synthesis of zinc oxide nanoparticles under ambient conditions. Significant changes in the nanoscale morphology of ZnO have been observed, using scanning electron microscopy, with respect to changes in pH and gas atmosphere of the medium. More specifically, hexagonal plates of nanoscale ZnO were formed at pH below the isoelectric point of the enzyme and spherical particles at alkaline pH. Interestingly the average particle size of ZnO nanostructures increases with increasing oxygen content at acidic pH while the opposite trend is noticed at alkaline pH. The observations are explained on the basis of changes in the enzyme's surface charge, conformation and redox potential using a combination of techniques like zeta potential measurements, FTIR spectroscopy, fluorescence spectroscopy, open circuit potential studies and cyclic voltammetry. Thus the present work demonstrates the applicability of an enzyme as a dynamic bio-template for the synthesis of a multitude of ZnO nanostructures which are expected to add newer insight into bottom-up fabrication of oxide nanostructures.
authors.affiliation: Centre for Nanotechnology & Advanced Biomaterials, School of Chemical & Biotechnology, SASTRA University, Thanjavur, Tamil Nadu 613 401, India.
authors.forename: Gunavadhi
authors.initials: G
authors.lastname: Murugappan
authors.affiliation: Centre for Nanotechnology & Advanced Biomaterials, School of Chemical & Biotechnology, SASTRA University, Thanjavur, Tamil Nadu 613 401, India. Electronic address: meerasarathy07@gmail.com.
authors.forename: Meera
authors.initials: M
authors.lastname: Parthasarathy
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D008958:Models, Molecular; D010316:Particle Size; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared; D013552:Swine; D015034:Zinc Oxide / Q000737:chemistry* / Q000378:metabolism
chemical_list: D006631:Amine Oxidase (Copper-Containing); D015034:Zinc Oxide
keywords: Biosynthesis; Biotemplate; Diamine oxidase; Nanomaterial; Zinc oxide