Ultrathin ZIF-67 nanosheets as a colorimetric biosensing platform for peroxidase-like catalysis.

In this work, we report a zeolitic imidazolate framework (ZIF-67) which could catalyze 3,3',5,5'-tetramethylbenzidine (TMB) to produce a yellow chromogenic reaction. ZIF-67 showed high peroxidase-like activity compared with copper-based metal-organic framework nanoparticles (Cu-MOF), zinc-based metal-organic framework nanoparticles (ZIF-8), and horseradish peroxidase (HPR). We discovered for the first time that the cobalt-based metal-organic framework nanoparticles possess intrinsic peroxidase-like activity without H2O2, which can be employed to quantitatively monitor the H2O2. Graphical abstract ᅟ.