Studies Of Electrochemical (bio) Sensors Based On The Graphene/Polymer Composites

As a hot topic in the research of modern analytical chemistry, the biosensor is a subject by chemistry, biology, medicine, physics, electronic technology and other subjects of mutual penetration grew up, with high sensitivity, good selectivity, fast analysis speed, low cost and simple operation etc.In the areas of clinical diagnosis, food industry, environmental monitoring have been high concern and widely used. In this paper, we construct a new type of excellent performance of polyacrylic acid functionalized graphene immobilized glucose oxidase biosensors(rGO-PAA/GOD) and polyacrylic acid functionalized graphene immobilized hemoglobin biosensors(rGO-PAA/Hb), and which are used in detecting glucose, hydrogen peroxide(H2O2) and nitric oxide(NO), with satisfactory results. In addition, this paper constructed a new type of polyethyleneimine(PEI) functionalized graphene phenol electrochemical biosensors, and applied to detect acetyl amino phenol(AP), with satisfactory results. The main research is summarized below:(1)Using reducing graphene oxide(rGO) and polyacrylic acid(PAA) prepared polyacrylic acid functionalized graphene composites(rGO-PAA) and rGO-PAA immobilized glucose oxidase(GOD), constructed a new type of polyacrylic acid functionalized graphene immobilized glucose oxidase biosensors(rGO-PAA/GOD). The direct electrochemical behaviors of rGO-PAA/GOD/GCE were studied by cyclic voltammetry. With the amperometric detection of glucose concentration.The results showed GOD immobilized in the rGO-PAA film not only retained its bioactivity, and promotes the electron transfer between GOD and glucose. the linear detection range was from 2.7 mM to 21.6 mM with the limit of detection(LOD) of 0.045 mM(S/N = 3). Used to detect glucose concentration in the blood plasma, the recovery is very good.(2)Using rGO-PAA immobilized hemoglobin(Hb), constructed a new type of polyacrylic acid functionalized graphene immobilized hemoglobin biosensors(rGO-PAA/ Hb).The results showed Hb has a good electrochemistry behavior on the modified electrode. Determination of H2O2 and NO concentration with the amperometric response, H2O2 concentration between 1.2 ?M and 4.8 ?M had a good linear relationship, and the LOD is 0.054 ?M(S/N = 3); NO concentration between 1.8 ?M and 52.2 ?M had a good linear relationship, and the LOD is 0.12 ?M(S/N = 3).(3)Using reducing graphene oxide(rGO) and polyethyleneimine(PEI) prepared polyethyleneimine functionalized graphene nanocomposites(rGO-PEI), and rGO-PEI directly modified glassy carbon electrode was constructed phenol electrochemical biosensors. The sensor of acetaminophen(AP) has a good detection results, AP concentration between 0 ?M and 48 ?M has a good linear relationship, AP concentration between 48 ?M and 210 ?M has a good linear relationship, and the LOD is 0.14 ?M(S/N = 3). Used to detect AP concentration in the cold tablet, the recovery is very good.