In-situ growth of Co 3 O 4 nanoparticles on mesoporous carbon nanofibers: a new nanocomposite for nonenzymatic amperometric sensing of H 2 O 2

The paper describes a nonenzymatic amperometric H 2 O 2 sensor that uses a nanocomposite consisting of Co 3 O 4 nanoparticles (NPs) and mesoporous carbon nanofibers (Co 3 O 4 -MCNFs). The Co 3 O 4 NPs were grown in situ on the MCNFs by a solvothermal procedure. The synergetic combination of the electrocatalytic activity of the Co 3 O 4 NPs and the electrical conductivity of MCNFs as an immobilization matrix enhance the sensing ability of the hybrid nanostructure. The oxidation current, best measured at 0.2 V (vs. SCE) is linear in the 1 to 2580 μM H 2 O 2 concentration range, with a 0.5 μM lower detection limit (at an S/N ratio of 3). The sensor is highly selective even in the presence of common electroactive interferents. It was applied to the determination of H 2 O 2 in spiked milk samples. Graphical abstract Schematic of the synthesis of a nanocomposite consisting of Co 3 O 4 nanoparticles (NPs) and mesoporous carbon nanofibers (Co 3 O 4 -MCNFs) by a solvothermal procedure. It was used as electrocatalyst for direct oxidation of H 2 O 2 .