Greener saponin induced morphologically controlled various polymorphs of nanostructured iron oxide materials for biosensor applications

Abstract

Presently, the progress of green chemistry in the synthesis of magnetic nanoparticles with the use of plants has engrossed a great attention, that do not employ toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. Here, it is a report on rapid, energy-efficient, green and economically scalable room temperature protocol for the synthesis of different polymorphs of iron oxide nanostructures such as Fe₃O₄ nanospheres, γ-Fe₂O₃ nanoribbons and α-Fe₂O₃ nanospheres using greener saponin as a bio-surfactant with tunable magnetic properties directed by particle shape. A bio-surfactant directed growth mechanism was proposed for the magnetic anisotropic structure formation and the aspect ratio can be controlled by changing reaction conditions. The electrochemical sensing properties of the as obtained γ-Fe₂O₃ nanoribbon and α-Fe₂O₃ nanospheres modified glassy carbon electrode (GCE) towards dopamine and uric acid with different morphologies were investigated systematically. The electrochemical dynamic results confirmed that the superior electron transport ability of nanostructures exhibited a higher anodic current response with a negative shift in positive potential than the bare GCE. The γ-Fe₂O₃ nanoribbon showed 100% enhanced electrochemical sensing performance compared to the α-Fe₂O₃ nanospheres. These studies suggested that non-spherical iron oxide nanoparticles (NPs) could potentially lead to further advancement in nanomedicine.