Facile preparation of mesocellular graphene foam for direct glucose oxidase electrochemistry and sensitive glucose sensing

• Developing a scale-up method to synthesize mesocellular graphene foam (MGF).
• MGF has ultra-large surface area (2581 m2 g−1) and large pore volume (5.53 cm3 g−1).
• Effectively and directly immobilizing GOD in pristine MGF with high loading capacity.
• Realizing the fast and direct electron transfer of GOD and sensitive glucose sensing.
• A potential matrix for novel biosensor preparation based on MGF.

Biocompatible mesocellular graphene foam (MGF) was easily synthesized and conveniently used for the immobilization, direct electrochemistry, and biosensing of glucose oxidase (GOD). Detailed characterization revealed that the as-prepared MGF has high conductivity, ultra-large surface area (2581 m2 g−1) and pore volume (5.53 cm3 g−1) as well as high loading of GOD. When the pristine MGF served as a glucose biosensor, the direct and fast electron transfer with rate constant of 4.8 s−1 was observed by cyclic voltammetry measurements. Based on the decrease of electrocatalytic currents, the prepared biosensor exhibited a wide linear range from 1.0 to 12 mM with a detection limit of 0.25 mM and a sensitivity of 2.87 μA mM−1 cm−2. Furthermore, the repeated and long-run test showed that the glucose biosensor was stable in both direct electrochemistry and sensitive glucose sensing. All these features besides the facile preparation, suggested that MGF would be a potential matrix for novel biosensor preparation.