Graphene quantum dots (GQDs)-modified screen-printed electrode for the determination of cannabidiol (CBD) in hemp seeds flour

In this work, the development of a graphene quantum dots (GQDs)-modified screen-printed carbon (SPCE) electrode for the determination of cannabidiol (CBD), a cannabinoid present in the Cannabis L. Sativa (hemp) plant, is reported. This cannabinoid is non-intoxicating and non-psychoactive, thus CBD-containing drugs as well as CBD-containing foods, are now on the market in many countries due to their health-beneficial effects and pharmacological activities. Because of the increasing interest in analyzing CBD in these real samples, we analyzed here a sample of hemp flour that was used for testing the developed CBD electrochemical sensor. Preliminary work devoted to optimizing the analysis conditions, allowed to development of a GQDs-modified electrode with promising characteristics for the simple screening of CBD. The electroanalytical tests for CBD detection showed a sensitivity of 0.98 μAμM-1 cm−2, which is increased by 2-folder compared to bare SPCE, and a limit of detection (LOD) equal to 0.277 μM. The developed GQDs/SPCE sensor and the analysis procedure were then applied for the CBD analysis in a hemp seeds flour sample. Based on the results obtained, the advantages/disadvantages evidenced by operating with the developed electrochemical sensor in the analysis of CBD in real samples were discussed.