Co 3 O 4 Nanoparticles Uniformly Dispersed in Rational Porous Carbon Nano-Boxes for Significantly Enhanced Electrocatalytic Detection of H 2 O 2 Released from Living Cells.

A facile and ingenious method to chemical etching-coordinating a metal-organic framework (MOF) followed by an annealing treatment was proposed to prepare Co 3 O 4 nanoparticles uniformly dispersed in rational porous carbon nano-boxes (Co 3 O 4 @CNBs), which was further used to detect H 2 O 2 released from living cells. The Co 3 O 4 @CNBs H 2 O 2 sensor delivers much higher sensitivity than non-etching/coordinating Co 3 O 4 , offering a limit of detection of 2.32 nM. The wide working range covers 10 nM-359 μM H 2 O 2 , while possessing good selectivity and excellent reproducibility. Moreover, this biosensor was used to successfully real-time detect H 2 O 2 released from living cells, including both healthy and tumor cells. The excellent performance holds great promise for Co 3 O 4 @CNBs's applications in electrochemical biomimetic sensing, particularly real-time monitor H 2 O 2 released from living cells.