In‐situ synthesis of magnetic Ce‐BDC@Fe 3 O 4 metal–organic frameworks and their multiple enzyme‐mimicking catalysis

Abstract

In this work, we used nano-magnetic fluid to magnetize Ce-BDC metal–organic framework (MOF) (BDC = 1,4-benzenedicarboxylic acid) by using Fe3O4-based nano-magnetic fluid grown in situ around a Ce-BDC core. The obtained Ce-BDC@Fe3O4 nanohybrid are mixed-valence MOFs, which could directly oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) into oxTMB without the presence for H2O2. Significantly, the coupling of both Fe3O4 nano-magnetic fluid and Ce-BDC MOF exhibits 0.25-fold higher catalytic activity than Ce-BDC MOF under the same conditions, indicating that the synergistic enhancement occurred in the catalytic activity. This boost is benefited from the more superoxide radicals (O2•−) and then more hydroxyl radica (•OH) with the deposition of Fe3O4 nano-magnetic fluid, which was generated by Ce-BDC@Fe3O4 nanohybrid as both oxidase and peroxidase mimics. In view of high catalytic activity and easy recovery by applying an external magnet, a novel, simple and sensitive Vitamin C colorimetric detection could come true in the wide range (0–120 μM) with a correlation coefficient (R2) of 0.995.