Structural tuning of CTAB@MgFe2O4 nanocomposite as peroxidase mimic for H2O2 and glucose sensing

Abstract

Natural enzymes have been used in food industry, biosensing and pharmaceuticals due to their high catalytic activity. Their catalytic potential is governed by the environmental conditions leading to their denaturation, thus increasing operational cost. Nanoparticles (NPs) as enzyme mimic is a thrust area of research. Magnesium ferrite nanoparticles (MgFe2O4 NPs) have gained focus of researchers due to good catalytic activity, stability and magnetic properties. Their catalytic activity can be enhanced by surface coating with suitable surfactant. In this work, CTAB (cetyl trimethyl ammonium bromide) coated MgFe2O4 NPs were prepared and evaluated as peroxidase mimics. The XRD pattern of MgFe2O4 NPs confirmed single-phase formation of spinel structure with cubic geometry. FT-IR studies confirmed the presence of CTAB along with MgFe2O4 NPs. Surface area, Particle size and magnetic character of the NPs were evaluated by Brunauer Emmett Teller analysis, Transmission Electron Microscope and Vibrating Sample Magnetometer respectively. CTAB coated ferrite NPs showed increased surface area and decreased particle size as compared to pristine NPs. CTAB@MgFe2O4 in w/w ratio (1:1) showed best peroxidase like activity towards o-dianisidine dihydrochloride and was influenced by pH, temperature and substrate concentration in solution. The synthesized CTAB@MgFe2O4 (1:1) based system could be used for colorimetric detection of H2O2 in the linear range of 20–300 μM with a detection limit of 10 μM and also for the detection for glucose in the range of 10–1000 μM with a detection limit of 5 μM.