Abstract: This study aimed to develop a method for rapid and precise detection of melamine in milk products. Based on the phenomenon that the melamine can linearly increase the fluorescence intensity of fluorescein within a certain concentration range, we constructed an eggshell membrane biosensor with fluorescein immobilized on its surface to detect melamine. Fluorescein and glutaraldehyde concentration were optimized. The eggshell membrane sensor had a linear working range of 1–500 μg/L, and the limit of detection (LOD) for melamine was 0.47 μg/L. Compared to the methods used for the detection of melamine in aqueous solution, the eggshell membrane sensor was more specific and stable with higher selectivity and lower LOD. This sensor can be successfully applied to the detection of melamine in commercial milk products.

Key words: egg membrane, fluorescein, melamine, sensor