Rapid electrochemical lateral flow device for the detection of Δ9-tetrahydrocannabinol.

Cannabis is a plant that is harmful and beneficial because it contains more than 400 bioactive compounds, and the main compounds are Δ9 tetrahydrocannabinol (THC) and cannabidiol (CBD). Currently, cannabis extracts are used in medicine, but the amount of THC as a main psychoactive component is strictly regulated. Therefore, the ability to rapidly and accurately detect THC is important. Herein, we developed a sensitive electrochemical method combining a rapid lateral flow assay (LFA) to detect THC rapidly. An electrochemical LFA device was constructed by attaching a screen-printed electrode inside a lateral-flow device to exploit the remarkable binding of THC to the cannabinoid type 2 (CB2) receptor in the test zone. The ferrocene carboxylic acid attached to the monoclonal THC antibody acts as an electroactive species when it binds to the THC in the sample before it flows continuously to the CB2 receptor region on the electrode. Under optimal conditions, the detection time is within 6 min and the devise shows excellent performance with a detection limit of 1.30 ng/mL. Additionally, the device could be applied to detect THC in hemp extract samples. The results obtained from this sensor are similar to the standard method (HPLC) for detecting THC. Therefore, this proposed device is useful as an alternative device for the on-site determination of THC because it is inexpensive, portable, and exhibits high sensitivity.

Low-cost and disposable sensors for the simultaneous determination of coenzyme Q10 and α-lipoic acid using manganese (IV) oxide-modified screen-printed graphene electrodes.

In this work, for the first time, manganese (IV) oxide-modified screen-printed graphene electrodes (MnO2/SPGEs) were developed for the simultaneous electrochemical detection of coenzyme Q10 (CoQ10) and α-lipoic acid (ALA). This sensor exhibits attractive benefits such as simplicity, low production costs, and disposability. Cyclic voltammetry (CV) was used to characterize the electrochemical behavior of the analyte and investigate the capacitance and electroactive surface area of the unmodified and modified electrode surfaces. The electrochemical behavior of CoQ10 and ALA on MnO2/SPGEs was also discussed. Additionally, square wave anodic stripping voltammetry (SWASV) was used for the quantitative determination of CoQ10 and ALA. Under optimal conditions, the obtained signals are linear in the concentration range from 2.0 to 75.0 µg mL-1 for CoQ10 and 0.3-25.0 µg mL-1 for ALA. The low limits of detection (LODs) were found to be 0.56 µg mL-1 and 0.088 µg mL-1 for CoQ10 and ALA, respectively. Moreover, we demonstrated the utility and applicability of the MnO2/SPGE sensor through simultaneous measurements of CoQ10 and ALA in dietary supplements. The sensor provides high accuracy measurements, exhibiting its high potential for practical applications.