MOF-derived N-doped porous carbon anchoring atomically-dispersed Fe for electrochemical sensing of paracetamol

Establishing an efficient and sensitive electrochemical sensor for paracetamol (PCM) is of significant importance in pharmaceutical quality control and environmental protection. This paper reports a novel electrochemical sensing platform based on a ZIF-8-derived strategy for fabricating N-doped porous carbon with monodispersed Fe-N x sites (Fe-N/NPC). The introduction of iron phthalocyanine (Fe-Pc) molecules fixed within the ZIF-8 framework prevents the aggregation of metal species during high-temperature treatment, ensuring the high dispersion of Fe-N x sites. Under optimized conditions, Fe-N/NPC-10/GCE electrochemical sensor exhibits excellent performance for PCM detection, which is mainly attributed to the synergistic enhancement between Fe-N x and NPC. The high surface area of NPC with a porous structure and N doping effect, which enhances its adsorption capacity for PCM, facilitating electron transfer and thereby amplifying the response signal. At the same time, the high-density monodispersed Fe-N x provides abundant catalytic active sites, improving electrocatalytic activity. Through the investigation of how buffer solution pH affects the oxidation peak induced by PCM, a pH of 7.0 was ultimately determined to be the optimal value. Using differential pulse voltammetry (DPV), the Fe-N/NPC-10/GCE electrochemical sensor demonstrates a wide detection range (0.1–10, 10–150 μM) for PCM with a detection limit (LOD) of 0.019 μM. Furthermore, the sensor exhibits good selectivity, stability, and reproducibility, and has been successfully applied for the determination of PCM in real pharmaceutical samples, with a recovery rate close to 100 %, indicating that the analytical method performs well and is suitable for analysis of real samples.