Preparation And Electrochemical Properties Of Graphene Solid Heteropolyacid New Sensor

Graphene (GR) has unique physical and chemical properties, which makes it widely the favor of the researchers in the biosensor. It does not only has large specific area, but has more binding sites after functionalization, which can be used to combine other nanomaterials. Heteropoly acid is a kind of metal cluster compounds with unique structure and physical and chemical properties. It has been widely used in catalysis, medicine, materials science, biology, and other fields for its thermal stability and redox properties. In our work, we took GR and heteropoly acid as the main material to modify electrode, and also studied the electrochemical behavior of folic acid, glucose, dopamine on the modified electrode.Based on the sensitive inhibitory activity of folic acid (FA) towards the redox behaviour of Keggin-type phosphomolybdic acid, a novel phosphomolybdic acid-polypyrrole/graphene composite modified glassy carbon electrode (GCE) is fabricated. The integration of GR endows the modified GCE with more active sites, which is favorable for the sensitive determination of FA. The redox behavior of the modified electrode is investigated by cyclic voltammetry (CV) and the electrochemical behavior of FA is studied by differential pulse voltammetry (DPV).With phosphomolybdic acid functionalized GR first, and then used layer by layer assembly method and electroplating copper nanoparticles to construct Cu/PMo12-GR modified electrode. A new glucose sensor was successfully achieved. On the modified electrode, the excellent electrochemical performances were obtained, such as an enhanced electrocatalytic property, high sensitivity, excellent selectivity and satisfactory stability towards oxidation of glucose.A new type of poly (sulfosalicylic acid)/graphene modified electrode (PSA/GR/GCE) was fabricated by dispensing graphene (GR) on GCE and then electro-polymerized PSA onto GR/GCE with cyclic voltammtry method. It can be used for highly selective and sensitive detection of dopamine (DA) even in the presence of mass ascorbic acid (AA) due to the excellent properties of biochemical composite materials...