Highly sensitive detection and mechanism study of tetracycline in water by CuFeO2/NiCo-LDH heterojunction electrochemical sensor

A CuFeO 2 /NiCo-LDH heterojunction electrochemical sensor (LDH: layered double hydroxide) was developed for the sensitive detection of tetracycline (TC). The sensor was constructed by integrating ZIF-67-derived nanocage NiCo-LDH on nickel foam with CuFeO 2 , forming a p-n heterojunction that enhanced electron transfer and TC adsorption. The sensor exhibited bilinear detection ranges (0.00594 ~ 1 and 1 ~ 25 μM) and a low detection limit of 1.98 nM. Recoveries in real water samples ranged from 92.0 to 109.0%, with relative standard deviations not exceeding 4.5%. In situ Raman spectroscopy and density functional theory calculations confirmed the involvement of multiple redox pairs (Ni 3+ /Ni 2+ , Co 3+ /Co 2+ , Fe 3+ /Fe 2+ and Cu 2+ /Cu + ) and strong interfacial adsorption energy. This sensor presents a practical and efficient approach for onsite TC monitoring. Graphical