Nanospheres and nanoleaves of γ-Fe2O3 architecturing for magnetic and biomolecule sensing applications

Acicular 1D iron oxide nanostructures such as needles, nanorods, and nanowires are attracted much attention owing to their enhanced optical, magnetic, catalytic and mechanical properties over spherically shaped nanoparticles. In this article, we have reported the highly crystalline monodispersed thermally stable gamma-Fe2O3 nanosphere (20 nm) and gamma-Fe2O3 nanoleaves (8 mu m) and FeO nanospheres (20 nm) synthesis using a facile nanoarchitecturing biosurfactant method. Characteristics of the iron oxide nanostructures were examined with field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimeteric analysis/differential thermogravimetric analysis (TG/DTA), fourier transform infrared spectroscopy (FTIR), Vibrating sample magnetometer (VSM) and cyclic voltammetry (CV) electrochemical analysis. Taking advantage of the saponin with big polar head and long hydrocarbon chain, it has become possible to template the synthesis of gamma-Fe2O3 nanosphere and Aloe Vera Leaf (AVL) like nanostructures controlling the reaction time and Sapinduss Mukkorossi Fruit Extract (SMFE) concentration. The satellite peaks appeared at 718.5 eV and 716 eV respectively and XRD confirmed the formed gamma-Fe2O3 nanodots are unidirectionally colloid and coalescence via 303 plane to form gamma-Fe2O3 nanoleaves at lower surfactant, however at higher surfactant FeO spheres. Defect free gamma-Fe2O3 nanoleaves demonstrates a higher magnetization of 13.8-9 emu/g due to the absence of coherent rotation of the magnetic moment caused by the larger width of nanoleaves. It was revealed that the gamma-Fe2O3 nanoleaves and gamma-Fe2O3 nanospheres exhibite the uric acid oxidation at a reduced potential of 303 +/- 3 mV with 150% and 80% enhanced electrocatalytic current respectively than GCE. This facile synthetic approach offers a greener alternative route for the synthesis of iron oxide nanostructures that are devoid of cellular and toxic chemical components. The synthesized nanomateials will find usage in magnetic storage devices, biomedical and electrocatalytic biosensor fields. (C) 2016 Elsevier B.V. All rights reserved.