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 µm 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 µM glucose ( S / N = 3), a linear detection range up to 6 mM, and high sensitivity of 14.17 µA/(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 high-performance biosensors.