Coral-like cobalt/nitrogen-doped porous carbon synergized with MnO₂ for ultrasensitive electrochemical detection of luteolin in floral teas

High-performance electrode materials are crucial for electrochemical sensing of bioactive food compounds. We report an eco-friendly synthesis of coral-like cobalt/nitrogen-doped porous carbon (Co/N-PC) via hydrothermal-pyrolysis, integrated with MnO₂ to construct a Co/N-PC@MnO₂/GCE sensor for ultrasensitive luteolin (LU) detection. Synergy between the conductive Co/N-PC framework (electron transport) and MnO₂ nanoparticles (Mn 2+ /Mn 3+ /Mn 4+ catalysis) delivers exceptional performance: dual linear ranges (0.01–1 μM; 1–100 μM) and a record-low 4 nM detection limit. Kinetic studies confirm the apparent electron transfer number (n app  = 4) arises from MnO₂ mediation. The sensor demonstrated high practicality in complex floral teas (honeysuckle, chrysanthemum), achieving 77.2–103.6 % recoveries. This work provides both a sensitive, green LU detection method and elucidates a MnO₂ catalytic cycle mechanism, revealing new insights into LU's electrochemical pathway.