A Novel Glucose Biosensor at Glucose Oxidase Immobilized Graphene and Bismuth Nanocomposite Film Modified Electrode

We have prepared graphene-bismuth nanoparticle (Bi) nanocomposite by simple solution based chemical reduction method and explored its biosensor application for the enzymatic determination of glucose. The characterization results revealed the successful formation of the composite. The graphene-Bi nanocomposite was used for the immobilization of glucose oxidase (GOx). Direct electron transfer of GOx was observed with well-defined redox peaks at the formal potential of - 0.427 V. The amount of electroactive GOx (Gamma) and electron transfer rate constant (k(s)) were calculated to be 5.48x10(-10) mol cm(-2) and 5.57 s(-1), respectively. An amperometric glucose biosensor has been fabricated which detects glucose in a wide linear range from 1 mM to 12 mM with high sensitivity (2.243 mu AmM-1 cm(-2)). Practical feasibility of the biosensor is explored in human blood serum sample which are revealed the excellent practicality of the biosensor. Moreover, the sensor exhibited appreciable stability, repeatability and reproducibility.