Development of an electrochemical sensor using carbon nanotubes and hydrophobic natural deep eutectic solvents for the detection of α-glucosidase activity in extracts of autochthonous medicinal plants

Imagine a sensor so sensitive it can detect a diabetes-related enzyme in medicinal plants—using a green solvent made from thyme and lactic acid. This is the first time such a combination has been used to build an electrochemical sensor.

For the first time, scientists have paired carbon nanotubes with a hydrophobic natural deep eutectic solvent (H-NADES) to create an electrochemical sensor that measures the activity of α-glucosidase, an enzyme linked to type 2 diabetes. The sensor uses the product of the enzyme's reaction as a probe, which contains two redox groups that generate the signal. By dispersing carboxylated multi-walled carbon nanotubes in a H-NADES made from thymol and lactic acid, the team boosted the electrode's electroactive surface area and electron transfer. This clever design allowed detection of α-glucosidase in a range of 0.004–0.1 U mL⁻¹, with a detection limit of 0.0013 U mL⁻¹—lower than most existing methods. To test real-world applications, the researchers screened two known inhibitors (acarbose and quercetin) and two plant extracts (Schinus molle and Eugenia uniflora). The IC50 values were 5.37 μg mL⁻¹ and 5.28 μg mL⁻¹, respectively, showing the sensor's potential for discovering antidiabetic drugs. This work marks the dawn of using NADES in sensor design, opening doors for greener, more sensitive electrochemical analysis.

Key Points

• First use of H-NADES as dispersant for carbon nanotubes in sensors.
• Detection limit 0.0013 U mL⁻¹, lower than most existing methods.
• Screened inhibitors and plant extracts for antidiabetic potential.