Abstract: In this experiment, gold magnetic nanoparticles (Fe3O4@Au) were formed by the self-assembly of Fe3O4 nanoparticles, prepared using the hydrothermal method, after surface amination. The performance of Fe3O4@Au was characterized. A simple method for visual detection of glucose was established on the basis of its peroxidase mimicking activity combined with the fact that glucose oxidase (GOx) catalyzes glucose oxidation to produce H2O2, which reacts to form a color with 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) as a peroxidase substrate. The glucose detection system was optimized and the selectivity and recovery of the method were determined. The results showed that Fe3O4 functionalized with amino groups could be effectively loaded with gold nanoparticles, and the saturation magnetization of Fe3O4@Au was 43 emu/g. The optimum detection conditions were as follows: amount of Fe3O4@Au suspension 0.15 g/mL, temperature 70 ℃, and time 50 min. Under the optimized conditions, a good linear relationship was observed for glucose concentration within the range of 1–20 mmol/L with a correlation coefficient (R2) of 0.992 5. The limit of detection (LOD) was 2.45 μmol/L, and the recoveries for spiked samples were 96%–104%. The proposed method had good selectivity and stability. This study will broaden the application of nanoparticle enzyme mimics in food detection and provide a new idea for improving glucose detection in foods.

Key words: gold magnetic nanoparticles, enzyme mimic, glucose, food detection