N-doped carbon Co/CoOx with laccase-like activity for detection of epinephrine.

N-doped carbon Co/CoOx with laccase-like activity was directionally designed by pyrolyzing Co-coordination polymer and applied to detect epinephrine, which revealed a new preparation strategy for laccase mimics. The formation mechanism of the N-doped carbon Co/CoOx nanozyme was reconnoitered by a thermogravimetric-mass spectrometry system (TG-MS). N-doped carbon Co/CoOx exhibited outstanding laccase-like activity, and the Michaelis-Menten constant and maximum initial velocity were calculated to be 0.087 mM and 0.0089 μM s-1, respectively. Based on this principle, a simple colorimetric sensing platform was developed for the quantitative detection of epinephrine, which can be used to diagnose pheochromocytoma. In addition, the visual platform for detecting epinephrine exhibited a linear range of 3 to 20 μg mL-1 and a calculated detection limit of 0.42 μg mL-1. Therefore, the proposed colorimetric sensing platform is a promising candidate to be applied in precise early pheochromocytoma diagnosis.