Enhancing the peroxidase-like activity of MIL-88B by ligand exchange with polydopamine

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 51; no. 6; pp. 2262 - 2268
• Main Authors: Hu, Changzhi, Xiong, Yuhao, Liang, Ling, Zuo, Weiyuan, Ye, Fanggui, Zhao, Shulin
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 08.02.2022
• Subjects: Agglomerated defects; Catalytic activity; Dispersion; Electrical resistivity; Ligands; Low conductivity; Metal-organic frameworks; Peroxidase; Selectivity
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d1dt03832j

Metal-organic frameworks (MOFs) as nanozymes have been widely used in biosensing. However, MOFs have inherent defects of easy agglomeration, leading to the stacking of active surfaces. In addition, the low conductivity of MOFs is not conducive to the electron migration in the Fenton-like reaction, which leads to a further decrease in catalytic activity and severely restricts their application. In response to the above problems, it makes sense to develop a method to improve both the dispersion and conductivity of MOFs. Here, a simple ligand exchange method with polydopamine (PDA) was used to synthesize MOF PDA-MIL-88B. PDA-MIL-88B shows stronger peroxidase-like activity than MIL-88B. One reason is the good dispersibility of PDA-MIL-88B, which is conducive to exposing the active surface. In addition, the reduced electrochemical impedance of PDA-MIL-88B increases its electrical conductivity, which is favorable for electron migration in the Fenton-like reaction. As a result, PDA-MIL-88B can better catalyze 3,3′,5,5′-tetramethylbenzidine to achieve redoximorphic color changes. PDA-MIL-88B can be used to detect glucose in human serum with good sensitivity and selectivity. This work can provide a strategy for MOFs to enhance the enzyme-like activity. A simple ligand exchange method with polydopamine was used to synthesize PDA-MIL-88B with enhanced peroxidase-like activity.