Fabrication And Application Of Electrodes Modified By Novel Transition Metal Nanocomposites

Novel transition metal nanocomposites have been widely used in electrocatalysts,sensors and biosensors and other fields because of its unique physical and chemical properties.Therefore,the advance of electrochemical biosensor based on novel transition metal nanocomposites modified electrode has become one of research hotspots.This paper developed some novel transition metal nanocomposites which could be applied in the field of electrochemical biosensing,and further explored its application in the detection of H₂O₂,NO₂^-,and paraoxon.The main contents were described as below:1.CoS₂ and NiS₂ were prepared by hydrothermal method,and the effects of different reaction surfactants and solvent on electrochemical properties of CoS₂ had been studied.Moreover,CoS₂ and NiS₂ were respectively mixed with ionic liquid?IL?to form two stable composite films,which were used to immobilize myohemoglobin?Mb?on carbon paste electrodes?CPE?.Furthermore,the Mb/CoS₂/IL-CPE modified electrode was used as a biosensor and exhibited lower detection limit to H₂O₂.2.A facile synthesis method at room temperature was achieved to synthesize CoB,and grow Ni?OH?₂ nano-sheets on the surface?CoB@Ni?OH?₂?.Two biocompatible platforms based on CoB/IL and?CoB@Ni?OH?₂?/IL composite film were applied to immobilize hemoglobin?Hb?.However,through this novel structural design,the electrochemical properties of the material had no improved.The Hb/CoB/IL-CPE showed excellent electrocatalytic activity towards NO₂^-with a low detection limit of3×10^-77 M.3.Fe₂O₃@C was derived from annealing of Fe-1,3,5-benzenentricarboxylate,and then its composition and morphology were confirmed by scanning electron microscopy?SEM?,X-ray diffraction?XRD?and energy dispersive spectroscopy?EDS?.Moreover,two biosensors based on Fe₂O₃@C and ionic liquid?IL?/nafion?NF?for sensing analysis of H₂O₂ and paraoxon were investigated by immobilizing Mb and acetylcholinesterase?AChE?on carbon paste electrodes?CPE?,respectively.Electrochemical studies demonstrated that as-prepared biosensors exhibited excellent electrochemical performance towards H₂O₂ and paraoxon with the detection limit as low as 1.7×10^-7 M and 1.2×10^-1414 M,respectively.