A sensitive acetylcholinesterase biosensor based on NaOH etching glassy carbon electrode for electrochemical determination of 3-nitropropionic acid

In this study, a stable and sensitive acetylcholinesterase biosensor was developed for the electrochemical determination of 3-nitropropionic acid (3-NPA). To this end, NaOH etching was used to activate the surface of the glassy carbon electrode, and the morphologies and electrochemistry properties of the resulting electrodes were characterized by various analytical methods. The results indicated dramatic enhancement in the electrochemical properties of electrodes by NaOH etching. As a result, the etched electrodes were applied as novel platforms for the immobilization of acetylcholinesterase. Accordingly, a sensor based on inhibition of 3-NPA toward the activity of acetylcholinesterase was constructed for the electrochemical determination of 3-NPA.Under the optimal conditions, the inhibition rate was found to be proportional to thelogarithm of the concentration of 3-NPA from 0.1 to 30 μg/L, and the limit of detection was recorded as 0.05 μg/L. In comparison to conventional detection method, the fabricated biosensor also has added advantages in the form of easy and convenient operation, high sensitivity and better linear range.