Graphene/Polymer/Redox Protein Based On Electrochemical Biosensors

The electrochemical biosensors developed by integrating biosensors with the electrochemical analytical method show board application prospects due to their advantages of high sensitivity,good selectivity, fast response, easy operation and low cost, etc. Graphene and its functionalized composites which are new types of carbon nanomaterials possessing perfect physical and chemical properties. This paper mainly prepared some new types of polymer functionalized graphene composites, and then the composites were used to immobilized galactose oxidase, hemoglobin or glucose oxidase to construct biosensor.The performance parameters of the constructed biosensor were obtained.The main content will now be summarized as follows:(1) Poly(methyl allyl polyethenoxy ether) functionalized graphene oxide(GO-HPEG) was synthesized to immobilize galactose oxide,GAO wad entrapped succfully into this comsite filml. Direct electrochemical behavior of this modified electrode was examined and the influence of buffer solution’s PH value and the influence of sweep rate were also studied. GAO in the composite film realized its direct electrochemistry and the biosensor exhibited excellent bioelectrocatalytic activity toward galactose and DHA with wide linear range and low detection limit.The linear detection range was from 8 μM to 412μM toward galactose with the limit of detection(LOD) of 3.0 μM and a wide linear range of 2 μM to 56 μM with LOD of 0.47 μM toward DHA(S/N = 3). Using this biosensor to detect galactose in honey, the recovery is 98.8% to 104.8%.Also, the biosensor exhibited good reproducibility and stability.(2) A composite film of graphene oxide and poly(methyl allyl polyethenoxy ether) was parpared. Hemoglobin wad entrapped succfully into this comsite film and realized its direct electron tranfer on glassy glassy carbon electrode,the rasults showed this composite film keeped the bioactivity of hemoglobin.Determination of H2O2 and NO were carried out by amperometry, and the amperometric response of the biosensor varied linearly ranging from 0.35 μM to 8.4 μM toward H2O2 with LOD of 2.7 nM and exhibited a wide linear range of 1.9 μM to 39μM with LOD of 11 nM.(3) Reduced graphene oxide(GO) and PMVMA were combined and successfully immobilized glucose oxidase. A novel glucose electrochemical biosensor was constructed based on GO-PMVMA/GOD modified electrode(GO-PMVMA/GOD/GCE). The direct electrochemical behaviors of GO-PMVMA/GOD/GCE were studied by cyclic voltammetry and the results showed that the GOD in the composite membrane showed a pair of well-shaped reversible redox peaks. Meanwhile, the biosensor had a good electrocatalytic capability to glucose, the linear detection range was from 0.4 mM to 10.8 mM with the limit of detection(LOD) of 0.087 mM.