Phenolic Hydroxyl Group–Carbon Dots as a Fluorescent Probe for the Detection of Hydrogen Peroxide and Glucose in Milk

In order to directly detect the concentration of glucose in milk, carbon dots (CDs) rich in phenolic hydroxyl groups were synthesized in one step as a fluorescent probe. We presented a new glucose oxidase (GOx)-mediated strategy to detect glucose, which allowed the quantitative analysis of hydrogen peroxide (H 2 O 2 ) and glucose. Furthermore, it was possible to detect H 2 O 2 and glucose directly in complex systems such as milk. The result in milk showed that the fluorescence of the CDs was quenched by H 2 O 2 with the concentration range from 1 to 100 μM linearly, and the correlation coefficient was 0.977 with a detection limit of 0.175 μM. Similarly, a linear correlation was built between the fluorescence of the CDs and the concentration of glucose in the range from 10 to 100 μM with a correlation coefficient of 0.968 and a detection limit of 0.686 μM. The recovery rate was 97.30–101.05%, which showed high sensitivity in the detection of glucose in milk. As far as we know, this was the first time that CDs were used as a fluorescent probe to detect glucose in milk directly, which removed the step of pretreating milk and provided a supplement and extension for the detection of glucose in fluorescent spectroscopy.