COF-derived multicore-shell FeCo nanoalloys@N-doped carbon for sensitive electrochemical detection of caffeic acid

Abstract

Caffeic acid is a key indicator of wine quality, but its sensitive and accurate detection remains challenging due to the lack of high-performance sensing materials. Metal/N-doped porous carbon (M/NPC) electrocatalysts with abundant catalytic sites are promising to address this issue. Herein, a FeCo nanoalloy encapsulated in NPC (FeCo@NPC) was designed and synthesized via a "covalent organic framework (COF) adsorption-pyrolysis" strategy. The COF template enabled homogeneous dispersion and stabilization of FeCo. The resulting FeCo@NPC exhibited hierarchical porosity, abundant metal-Nx sites, and strong bimetallic synergetic effects, leading to exceptional electrocatalytic activity towards caffeic acid oxidation. The constructed sensor achieved high sensitivity (5.195 and 0.895 mu A mu M- 1) and selectivity. It was successfully applied for caffeic acid detection in commercial tablets and wines, and further tracked changes in caffeic acid concentration in red wine over postopening time. This work provides a general design strategy for designing high-performance electrocatalysts for food quality control.