MOF-derived Co3O4@Co-Fe oxide double-shelled nanocages as multi-functional specific peroxidase-like nanozyme catalysts for chemo/biosensing and dye degradation

•Co3O4@Co-Fe oxide DSNCs is derived from ZIF-67 and Co-Fe Prussian blue analogue.•Co3O4@Co-Fe oxide shows higher peroxidase-like activity than Co3O4 and Co-Fe oxide.•Co3O4@Co-Fe oxide DSNCs show high PMS activating ability to degrade dye in water.•A sensitive chemo/biosensing assay for H2O2 and AChE with wide linear range.•Recyclability of Co3O4@Co-Fe oxide for AF degradation keeps 92.3% up to 10 cycles.