Flexible Co-Ni nanocomposites in situ synthesized on carbon fibers for highly sensitive electrochemical detection of H2O2

In this study, Co-Ni nanomaterials were in situ synthesized on carbon fiber paper substrates, termed Co-Ni paper. Scanning electron microscopy characterization demonstrates fabricated flake-like Co-Ni nanocomposites uniformly distribute on carbon fibers, forming three-dimensional continuous network structure. The fabricated sample is determined to be a mixture of Co, Ni and C elements according to energy-dispersive X-ray spectrometer analysis. Without any pretreatments, Co-Ni paper exhibits excellent electro-oxidation capabilities towards H₂O₂, such as an excellent detecting performance in a wide linear range of 0‒11.5 mM of H₂O₂, fast amperometric responses within 1 s, and a low detection limit of 2.53 μM. Along with these intriguing properties, the in situ-synthesized Co-Ni paper has a good anti-interference towards Na₂SO₄, ZnCl₂, glucose and NaCl during H₂O₂ detection. Moreover, the H₂O₂ electro-chemical sensor on Co-Ni paper also possesses excellent reproducibility, long-term stability and high mechanical stability. This Co-Ni-paper-based sensor is effective to determine H₂O₂ in blood samples, thus it is promising for electrochemical H₂O₂ sensing.