Simple fabrication of a highly sensitive glucose biosensor using enzymes immobilized in exfoliated graphite nanoplatelets Nafion membrane

A novel and highly sensitive electroanalytical sensing nanocomposite material is reported for the development of a glucose biosensor. Exfoliated graphite nanoplatelets (xGnP) were tested to enhance the sensing capability. The xGnP has a diameter of 1 mu m and a thickness of 10 nm, on average. The glucose biosensing interface was prepared by casting glucose oxidase and xGnP in a Nafion water-isopropyl-alcohol solution with a high concentrated organic solvent (85 wt%). The resulting biosensors showed rapid response time within 5 s, limits of detection of 10 mu M glucose (SIN = 3), a linear detection range up to 6 mM, and high sensitivity of 14.17 mu A/(mM . cm(2)) with an optimum glucose oxidase loading. The biosensors also showed good selectivity and long-term stability. These results indicate that xGnP can be an inexpensive alternative to carbon nanotubes for the fabrication of affordable hiahperformance biosensors.