Hollow graphitic nanocapsules as efficient electrode materials for sensitive Hydrogen peroxide detection

●This paper developed a method of synthesizing hollow graphitic nanocapsules (HGN).●HGNs were used as efficient electrode materials for sensitive, selective and reproducible hydrogen peroxide detection.●HGNs could be utilized as three-dimensional matrices to effectively immobilize enzymes, proteins and small molecules.●A reagentless amperometric biosensor was fabricated by simple coimmobilization of methylene blue and horseradish peroxidase on the HGN-coated electrode.

Carbon nanomaterials are typically used in electrochemical biosensing applications for their unique properties. We report a hollow graphitic nanocapsule (HGN) utilized as an efficient electrode material for sensitive hydrogen peroxide detection. Methylene blue (MB) molecules could be efficiently adsorbed on the HGN surfaces, and this adsorption capability remained very stable under different pH regimes. HGNs were used as three-dimensional matrices for coimmobilization of MB electron mediators and horseradish peroxidase (HRP) to build an HGN–HRP–MB reagentless amperometric sensing platform to detect hydrogen peroxide. This simple HGN–HRP–MB complex demonstrated very sensitive and selective hydrogen peroxide detection capability, as well as high reproducibility and stability. The HGNs could also be utilized as matrices for immobilization of other enzymes, proteins or small molecules and for different biomedical applications.