Magnetic and N–doped nanofibrous carbon microsphere with hierarchical porosity as a nanozyme for on-site and visual detection of glucose

Background On-site and rapid detection of glucose level in foods is important for monitoring and control glucose intake. Methods Magnetic and N–doped nanofibrous carbon microspheres (Fe@NCMs) with hierarchical porosity were designed as a novel nanozyme (Fe@NCMzyme), and the catalytic mechanism was investigated via the density functional theory (DFT) calculation. Therefore, Fe@NCMzyme sensor and point-of-care testing (POCT) platform were developed for glucose detection in food samples. Significant findings Fe@NCMzyme showed 3D porous structure, a larger surface area, and N–doped carbon material properties, resulting in an enhanced peroxidase (POD)–like activity. In Fe@NCMzyme, Fe 3 O 4 nanoparticles (FeNPs) act as catalytic centers and N–doped carbon nanofibers could be used as substrate binding sites. DFT results revealed that Fe–induced Fenton–like reaction was the main catalytic mechanism. The low detection limit and linear range of Fe@NCMzyme sensor was 0.247 μM and 1–900 μM, respectively. The excellent recovery ration in spiked food samples was 85.0 %–110.0 %. The applicability of Fe@NCMzyme sensor for glucose detection was verified by the commercial Glucometer. Furthermore, Fe@NCMzyme POCT platform was established and a linear detection range (10–900 μM) was obtained with low detection limit (3.125 μM). Importantly, Fe@NCMzyme POCT platform was realized visual, on–site, and rapid detection of glucose in food samples.