Interfacial Regulation of ZIF-67 on Bacteria to Generate Bifunctional Sensing Material on Chip for Qualifying Cell-Released Reactive Oxygen Species
Zhuanzhuan Shi, Fang Shi, Yunpeng Li, Xiaoshuai Wu, Zhengyang Liu, Liang Liu, Qianqian Fu, Chang Ming Li, Chunxian Guo
Abstract
Cell’s activities are highly dependent on signal molecules, of which reactive oxygen species of the superoxide anion (O 2 •– ) and hydrogen peroxide (H 2 O 2 ) are important ones that always work together to regulate biological processes such as apoptosis and oxidative stress. It is of significance to realize simultaneous qualification of O 2 •– and H 2 O 2 but it still faces challenges particularly in live-cell assay with a complex environment. We report the design of a bifunctional sensing material by interfacially regulating ZIF-67 on bacteria Shewanella putrefaciens to generate cobalt nanoparticles/nitrogen-doped porous carbon nanorods (Co/N-doped CNRs) and its sensing chip for qualifying cell-released O 2 •– and H 2 O 2 . Co/N-doped CNRs exhibit unique properties including porous structure for significantly increased reaction surface area and coordinating Co nanoparticles for rich active sites. The bifunctional Co/N-doped CNRs is used to fabricate the electrochemical sensing chip, which achieves a fast response time (0.5 s for O 2 •–, 1.9 s for H 2 O 2 ), a low detection limit (0.69 nM for O 2 •–, 2.25 μM for H 2 O 2 ), and a remarkably high sensitivity (792.30 μA·μM –1 ·cm –2 for O 2 •–, 153.91 μA·mM –1 ·cm –2 for H 2 O 2 ), among the best of reported bifunctional nanozymes.