Fabrication of -Fe2O3/rGO nanocomposite and its study for electrochemical glucose sensor and supercapacitor application

The demands of electrochemical glucose sensors without enzymes have gained considerable attention in the field of glucose sensors. Therefore, we have fabricated alpha-Fe2O3/rGO nanocomposite using the biosynthesis method. Syzygium aromaticum (clove) extract was used as a capping/stabilizing agent to synthesize alpha-Fe2O3/rGO nanocomposite. Synthesized alpha-Fe2O3/rGO nanocomposite was characterized by Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), Transmission electron microscopy (TEM), Powder X-ray diffraction (PXRD), X-ray Photoelectron Spectroscopy (XPS), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), and UV-visible spectroscopy techniques. The agglomerated rod-shaped morphology of synthesized alpha-Fe2O3/rGO nanocomposite was observed in SEM micrographs. The Brunauer-Emmett-Teller (BET) analysis shows the surface areas of 187.644 m2/g for alpha-Fe2O3/rGO nanocomposite. The cyclic voltammetry (CV) was used to evaluate the electrochemical glucose sensing performance of a glassy carbon electrode modified by alpha-Fe2O3/rGO nanocomposite and 5 % Nafion solution (Nafion/alpha-Fe2O3/rGO/GCE). The modified Nafion/ alpha-Fe2O3/rGO/GCE was found to improve electrochemical glucose sensing performance. The modified Nafion/ alpha-Fe2O3/rGO/GCE exhibited a high sensitivity and limit of detection of 327.92 mu A mM-1 cm-2 and 0.6 mM respectively for electrochemical glucose sensing. The modified Nafion/alpha-Fe2O3/rGO/GCE shows good selectivity for glucose sensing over ascorbic acid and dopamine. The cyclic voltammetry (CV), galvanostatic charge/ discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques were used for the evaluation of electrochemical supercapacitor performance of modified alpha-Fe2O3/rGO/stainless steel (alpha-Fe2O3/rGO/SS) electrode. The calculated values of specific capacitance, energy density, and power density for alpha-Fe2O3/rGO/SS electrode at the current density of 1 A/g were 310.2 F/g, 27.54 Wh/kg, and 309.71 W/kg respectively. These results indicate that the alpha-Fe2O3/rGO nanocomposite can be used as an electrochemical glucose sensor and supercapacitor.