Ficin encapsulated in mesoporous metal-organic frameworks with enhanced peroxidase-like activity and colorimetric detection of glucose

Ficin has been reported to possess peroxidase activity, but its applications in some respects have been limited because of its relatively low activity. Herein, a mesoporous metal-organic framework, PCN-333(Fe), was synthesized, which was selected to encapsulate ficin to form [email protected] (Fe). Compared with ficin, the peroxidase-like activity of [email protected] (Fe) toward 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation was about 3 times increase in the presence of H 2 O 2 , and followed classical Michaelis-Menten model. The kinetic parameters showed that stronger affinity and higher catalytic constant ( K cat ) of [email protected] (Fe) to both TMB and H 2 O 2 compared with ficin, and K cat of [email protected] (Fe) was increased by 3.65 folds and 3.59 folds for TMB and H 2 O 2 , respectively. Taking advantages of higher catalytic property of [email protected] (Fe), we developed a colorimetric method with high sensitivity and selectivity to detect glucose, which displayed a good linear response toward glucose in the range of 0.5–180 μM with a limit of detection of 97 nM. Furthermore, [email protected] (Fe) has been proven to successfully detect glucose in human serum, implying its great potentialities and wide applications as peroxidase mimics.