Ternary CTAB@Co₃O₄@GO nanocomposite as a promising superoxide dismutase mimic

In the present study, nanocomposite (NC) of cetyl trimethyl ammonium bromide (CTAB) coated cobalt oxide nanoparticles (Co₃O₄ NPs) with graphene oxide (GO), i.e., CTAB@Co₃O₄ @GO, was synthesized for superoxide dis- mutase mimic (SOD) activity. The NPs and NC were characterized using various analytical tools. X-ray diffraction patterns, Fourier transform infrared and scanning electron microscope–energy dispersive spectrum confirmed the presence of both GO and Co₃O₄ NPs in NC. Transmission electron microscope micrographs of NC showed GO nanosheets having CTAB-coated Co₃O₄ NPs on their surface. The NC was evaluated for SOD mimic activity using pyrogallol as a substrate. NC displayed maximum activity as compared to pristine GO and Co₃O₄ NPs. The results signified that the surfactant coating and embedding the NPs in the GO matrix helped in increasing the interaction of NC with the substrate molecules. Kinetics data was modelled using Michaelis–Menton equation. The calculated Km and Vmax values of NC were 0.0675 mM and 0.146 mol s –1 , respectively. Lower value of Michaelis constant Km as compared to the reported values, confirm its edge over other SOD mimics. Thus CTAB@Co₃O₄@GO NC holds potential for replacing natural enzyme in SOD- based enzymatic assay. (author)