期刊

Journal of Materials Chemistry B

标题

Enhanced peroxidase-like activity of MOF nanozymes by co-catalysis for colorimetric detection of cholesterol

作者

Shuishi Li,  Ling Liang,  Longfei Tian, Jia Wu, Yuhui Zhu, Yuan Qin, Shulin Zhao and  Fanggui Ye

摘要

Metal–organic frameworks (MOFs) have been widely used as nanozymes with a great development prospect due to their unique advantages. It is known that the current Fe-based or Cu-based MOF, etc., exhibits the catalytic activity of nanozymes through the Fenton catalytic reaction. And the conversion efficiency of the Fe3+/Fe2+ or Cu2+/Cu+ cycle is key to the catalytic activity. Therefore, we proposed a novel co-catalytic method to promote the reaction rate of the rate-limiting step of Cu2+/Cu+ conversion in the Fenton reaction of Cu2+/H2O2 to enhance the catalytic activity of the nanozymes. As a proof of concept, the MoCu-2MI nanozyme with high catalytic activity was successfully synthesized using Mo-doped Cu-2MI (2-methylimidazole). By using 3,3′,5,5′-tetramethylbenzidine (TMB) as the chromogenic substrate, MoCu-2MI exhibited higher peroxidase-like activity than pure Cu-2MI. Then, it was confirmed that the newly introduced Mo played a crucial co-catalytic role by characterizing the possible catalytic mechanism. Specifically, Mo acted as a co-catalyst to accelerate the electron transfer in the system, and then promote the Cu2+/Cu+ cycle in the Cu-Fenton reaction, which was conducive to accelerating the production of a large number of reactive oxygen species (ROS) from H2O2, and finally improve the activity. Ultimately, a biosensor platform combined with MoCu-2MI and cholesterol oxidase realized the one-step colorimetric detection of cholesterol in the range of 2–140 μM with the detection limit as low as 1.2 μM. This study provides a new strategy for regulating the activity of MOF nanozymes.

原文链接

https://pubs.rsc.org/en/content/articlelanding/2023/tb/d3tb00958k