2D Nb₂C MXene/COF Composite as Electrochemical Platform for the Stress Marker Epinephrine Detection

Epinephrine (or adrenaline) is a common stress marker secreted by the adrenal glands in response to stress. Monitoring epinephrine levels in real samples is therefore clinically relevant, as it provides information on the magnitude of stress experienced by an individual. Herein, we present the rational design of a covalently linked 2D Nb 2 C MXene/COF hybrid electrode as an electrochemical platform for the detection of epinephrine. The electrochemical oxidation of epinephrine to epinephrine quinone at the 2D Nb 2 C MXene/COF hybrid electrode was observed at +0.23 V vs Ag/AgCl. The proposed sensing platform exhibits a limit of detection of 1.09 μM ( N = 3) and a sensitivity of 0.215 μA μM –1 cm –2, with excellent selectivity and repeatability. Furthermore, this electrode was employed for the real-time analysis of spiked epinephrine in serum and urine samples.