Fig. 3: Enzymatic conformation study.

a The microenvironment of heme center of native HRP (adapted from PDB: 1hch). The colors used in heme center of HRP are: green for C atom; blue for N atom; red for O atom; the central Fe ion is highlighted as an orange ball. b The CD spectra of free HRP in water and HRP after incubating in DMF aqueous solution for 6 h. The volumes of DMF and deionized water were 0.3 mL and 9.0 mL, respectively, which was in agreement with the assembly system. c The H¹ ssNMR spectra of HRP@HOF-100 biocomposite and its physical mixed sample of HRP and HOF-100. d UV-Vis DRS of native HRP, HOF-100 and HRP@HOF-100. e The 0–5000 G region of the EPR spectra of native HRP, HOF-100 and HRP@HOF-100. f The UV-Vis spectra for free HRP and HRP@HOF-100 after 5 min reaction time. Inset is the photograph of corresponding output signal. Conditions: 0.1 mM H₂O₂. The concentrations of free HRP and HRP@HOF-100 (equivalent immobilized HRP) were 0.125 mg/mL. g Schematic representation of the Pt NCs labeling process. The structure of GOx is adapted from PDB: 1 gal. h High-magnification cryo-EM image of GOx-Pt NCs-encapsulated HOF-100. The monodispersed Pt NCs were highlighted in red circles.