The Construction Of The Novel Sensing Platform Based On Nitrogen Doped Graphene And The Detection For Purine

Nitrogen doped graphene receives widespread attention due to its large electrochemical effective area,strong catalytic ability,fast electron transfer rate and good biocompatibility.In this paper,nitrogen doped reduced graphene oxide?N-RGO?was successfully prepared by a facile strategy,and then two electrochemical sensors were constructed for detecting guanine and xanthine,respectively.The main research contents are as follows:1.Firstly,nitrogen doped reduced graphene oxide?N-RGO?was successfully prepared by a facie carbon thermal reduction method.The morphology,structure and electrochemical properties of N-RGO were investigated by transmission electron microscopy?TEM?,scanning electron microscopy?SEM?,atomic force microscopy?AFM?,X-ray diffraction?XRD?,Raman,X-ray photoelectron spectroscop?XPS?,and cyclic voltammetry?CV?.XPS indicated the content of nitrogen in the N-RGO accounted for 9.46%.AFM manifested the thickness of N-RGO is about 1.0 nm.The electrochemical experiments demonstrated that N-RGO possesses large electrochemical effective area,strong adsorptive ability and fast electronic mass transfer rate.It was believed that N-RGO is a promising candidate for applications in electrochemical sensors and biosensors.Moreover,N-RGO modified glassy carbon electrode?N-RGO/GCE?exhibited good electrochemical response toward the oxidation of guanine with a linear range covering 4.14×10^-73.71×10^-4 M,and the corresponding detection limit?LOD?of 1.38×10^-7 M?S/N=3?.Eventually,the proposed sensor could be used to monitor cell necrosis by means of detecting the increase of current response of guanine.Thus,this work is very meaningful in the field of biological cytology and pathology.2.On the basis of the first chapter,the dilute acetic acid solution with chitosan?CS?was used as the dispersant of nitrogen doped reduced graphene oxide?N-RGO?to improve the dispersivity,electronic mass transfer rate,biocompatibility,and electrochemical effective area of N-RGO.Then a novel electrochemical sensor for detection of xanthine was fabricated based on CS/N-RGO composites.It exhibited good electrochemical response toward the oxidation of xanthine with a linear range covering 2.99×10^-81.07×10^-4 M,and the corresponding detection limit?LOD?of9.96×10^-9 M?S/N=3?.In addition,the sensor was employed to explored the electrochemical oxidation mechanism of xanthine by cyclic voltammetry,confirming the electrochemical oxidation of xanthine could generate uric acid.Finally,the inhibition for the formation of uric acid by febuxoatat and allopurinol was researched by electrochemical method.