Gold nanoparticles decorated silicate sol-gel matrix embedded reduced graphene oxide and manganese ferrite nanocomposite-materials-modified electrode for glucose sensor application

Gold nanoparticles decorated on silicate sol-gel matrix embedded manganese ferrite (MnFe2O4)-reduced graphene oxide (rGO) nanocomposites were synthesized through a facile chemical method. The prepared samples were characterized by using powder X-ray diffraction (XRD), UV-vis absorption spectroscopy (UV-VIS), energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) analyses. The Au nanostructures on rGO-MnFe2O4 improved the electrocatalytic activity of the rGO-MnFe2O4@Au composite-materials-modified electrodes towards glucose oxidation. Cyclic voltammetry and amperometric methods were used to evaluate the electrocatalytic activity of the rGO-MnFe2O4@Au modified electrodes towards glucose oxidation in 0.1 M NaOH at a less-positive potential (0.2 V) in the absence of any enzyme or redox mediator. The nanocomposite-modified electrode (GCE/EDAS/rGO-MnFe2O4@Au) was successfully used for the amperometric sensing of glucose and the experimental detection limit of 10 M glucose was observed. The common interfering agents did not interfere with the detection of glucose. The present sensor showed good stability, reproducibility, and selectivity. The nanocomposite-modified electrode was successfully used for the determination of glucose in the urine sample.