Nature‐Inspired Construction of MOF@COF Nanozyme with Active Sites in Tailored Microenvironment and Pseudopodia‐Like Surface for Enhanced Bacterial Inhibition

Abstract

Metal–organic frameworks (MOFs) have sparked increasing interest in mimicking the structure and function of natural enzymes. However, their catalytic and therapeutic efficiency are unsatisfactory due to the relatively lower catalytic activity. Herein, inspired by nature, a MOF@COF nanozyme has been designed as a high‐efficiency peroxidase mimic, with the metallic nodes of MOFs as active centres, the hierarchical nanocavities produced by the growth of covalent organic frameworks (COFs) as binding pockets to form tailored pore microenvironment around active sites for enriching and activating substrate molecules, to perform enhanced bacterial inhibition. Furthermore, the pseudopodia‐like surface of the COFs “skin” enabled the system to catch the bacteria effectively for further amplifying the therapeutic efficiency of MOF‐based nanozyme. We believe that the present study will not only facilitate the design of novel nanozymes, but also broaden the biological usage of MOF/COF‐based hybrid materials.

Rational Design and Growth of MOF‐on‐MOF Heterostructures

“…With this method, TFPT molecules are first anchoring onto MOFs to have NH 2 ‐UiO‐66@TFPT, and DETH molecules are further reacting with the pre‐coated aldehyde groups to give a MOF@COF hybrid hetero‐framework, denoted as U@TDE (Figure 10i). The effective assembly of MOF‐on‐COF composites can to a large extent overcome the shortcomings of a single MOF material, such as its relatively low stability and easy breakage, [ 165 ] so as to realize their association with separate advantages to improve its performance rather than a single component.…”

Metal-Organic Frameworks (MOFs)-Based Nanomaterials for Drug Delivery

“…By changing the surface functionality from hydroxides to amine(s), amide(s), and imide(s), the payload efficiency of the selected drug increases by an average rate of 38%. Moreover, natural polymers and leaf extracts on the surface of Cr, Zr, and Zn MOFs can enhance the relative cell viability by the rate of 2-14%, improve stability up to 150 h, and provide considerable pH tolerance (3.5 < pH < 9) [30][31][32].…”

Nanozyme Applications: A Glimpse of Insight in Food Safety

“…According to previous reports, the colorimetric assay can become a versatile strategy for rapid detection of a wide variety of other bacteria and pathogens. Moreover, Zhang et al designed a MOF@COF nanozyme to perform enhanced inhibition of bacteria like E. coli and S. aureus , which demonstrate the possibility of nanozymes using as potential antibacterial agents ( Zhang et al, 2021 ). No matter in detections or antimicrobial applications, active centers, hierarchical nanocavities, and pore microenvironment within nanozymes always play important roles in their efficient catalytic activity.…”