High-performance electrocatalysts based core-shell SWCNHs@ZIF-67 heterostructure for ultrasensitive H2O2 sensing

Abstract

ZIF-67 is a Co-based zeolitic imidazolate framework material with both redox metal active sites and organic functional groups. Single walled carbon nanohorns (SWCNHs) is a novel horn-shaped carbon nanomaterial with abundant carbon active sites and high conductivity. SWCNHs@ZIF-67 heterostructure composites were prepared by environmental-friendly method with ZIF-67 as core and SWCNHs as shell, then were fixed on the surface of glassy carbon electrode (GCE) to obtain the electrochemical sensing platform for detecting H₂O₂. The as-proposed sensor (SWCNHs@ZIF-67/GCE) demonstrates excellent electrocatalytic performance for the reduction of H₂O₂ with two linearity scopes (0.50–150 µM, 150–400 µM) and a low detection limit of 0.15 μM, which is attributed to the synergistic electrocatalytic effect between ZIF-67 and SWCNHs. The as-fabricated sensor was satisfactorily used for H₂O₂ analysis in plasma samples, revealing an immense potential application in vitro assay of H₂O₂.