Functional Nanozymes Consisting of Co2+‐ZIF‐67 Metal‐Organic Framework Nanoparticles and Co2+‐ZIF‐67/Polyaniline Conjugates

Abstract Co 2+ ‐ZIF‐67 metal‐organic framework nanoparticles (NMOFs), act as nanozymes catalyzing diverse processes, including peroxidase, oxidase, and catalase activities. Peroxidase activities are reflected by the nanozyme‐catalyzed H 2 O 2 oxidation of dopamine to aminochrome, the H 2 O 2 oxidation of NADH to NAD + , the H 2 O 2 ‐catalyzed generation of chemiluminescence through oxidation of luminol, and the H 2 O 2 ‐mediated oxidation of aniline to polyaniline. Oxidase activities of the nanozyme are demonstrated by the Co 2+ ‐ZIF‐67 NMOFs catalyzed aerobic oxidation of dopamine to aminochrome and of NADH to NAD + , and catalase activities of the nanozyme are reflected by the catalytic decomposition of H 2 O 2 . Moreover, the Co 2+ ‐ZIF‐67 catalyzed oxidation of aniline to polyaniline (PAN) by H 2 O 2 is accompanied by the coating of NMOFs with PAN to yield a Co 2+ ‐ZIF‐67/PAN hybrid material. Coating the particles in the presence of guest substrates leads to molecular imprinted PAN matrices revealing enhanced ZIF‐67 catalyzed transformations as compared to non‐imprinted PAN matrices. This is demonstrated by imprinting of 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid), ABTS 2− , in the PAN coating and the 3.3‐fold enhanced catalyzed oxidation of ABTS 2− by H 2 O 2 , as compared to the non‐imprinted PAN hybrid composite. Moreover, imprinting of L‐/D‐DOPA in the PAN coating of Co 2+ ‐ZIF‐67 NMOFs leads to chiro‐selective H 2 O 2 ‐guided oxidation of L‐/D‐DOPA to dopachrome by the NMOFs/PAN composite.