Development of a MOF-based electrochemical sensor for trace detection of cannabidiol in biological, environmental, and plant-derived samples

The accurate determination of cannabidiol (CBD) is of growing importance due to its expanding therapeutic applications, legal regulation requirements, and the need for reliable quality control in biological, environmental, and plant-derived products. In this study, a novel electrochemical sensor based on a MOF-808-modified glassy carbon electrode (MOF-808/GCE) was developed for the sensitive and selective detection of cannabidiol (CBD). The sensor leveraged the high surface area and active sites of MOF-808, which incorporates six monotopic formate ligands, to enhance electrochemical performance. Using differential pulse voltammetry (DPV), the sensor demonstrated a wide linear range (0.02-5.0 mu M), excellent correlation (R2 = 0.997), and a low detection limit of 0.005 mu M. The modified electrode exhibited outstanding repeatability (RSD = 2.0 %) and reproducibility (RSD = 1.4 %). Interference studies confirmed high selectivity against common electroactive species. The sensor was successfully applied to determine CBD in complex real-world matrices, including human plasma, urine, lake and tap water, and Cannabis sativa extracts, with recoveries ranging from 98.38 % to 102.4 %. These results establish the MOF-808/GCE sensor as a robust and efficient tool for trace-level CBD analysis in biological, environmental, and plant-based samples.