Fabrication Of Graphene-based Mimic Enzyme And Its Application In Electrochemical Sensors

The graphene nanocomposites have excellent electrocatalytic properties and can be used to modify electrodes.Graphene as a carrier can improve the dispersibility of the active substances such as metal nanoparticles,and facilitate electron transport,thereby improving the catalytic activity against the substrate.The synergistic effect between graphene and nanomaterials has led to the development and construction of novel enzymeless biosensors,which possess highly sensitivity and excellent selectivity.In this paper,several graphene-based nanomaterials were prepared to constructed electrochemical biosensors.Their electrochemical performances were measured by cyclic voltammetry?CV?and chronoamperometry?I-t?and their sensitivity,selecrivity,stability and repeatability were tested,respectively.Details are as follows.?1?Zinc oxide-cobalt?II?oxide/rGO?ZnO-CoO/rGO?nanocomposite were synthesized by solvothermal method and calcination,and then was modified on the surface of glassy carbon electrode?GCE?.Due to the large specific surface area of grahene and the synergistic effect between graphene and nanomaterials,ZnO-CoO/rGO-GCE has excellent electrocatalytic activity.Experimental results show that by changing the working voltage,ZnO-CoO/rGO can be used as mimic enzyme of glucose oxidation,but also can have the effect on reduction of hydrogen peroxide?H₂O₂?,thus it can be used to build the multifunctional biosensor.?2?Cobalt-nickel sulfide/rGO?NiCo₂S₄/rGO?was synthesized by hydrothermal method and calcinations,and was then modified on GCE to prepared biosensors.As H₂O₂ mimic enzyme,the nanomaterial has high catalytic efficiency for the reduction of H₂O₂,and can be used for quantitative detection of H₂O₂.