Electrochemical acetylcholinesterase biosensor for detection of cholinesterase inhibitors: study with eserine

• Published in: Informacije MIDEM (Spletna izd.) pp. 235 - 240
• Format: Journal Article
• Language: English
• Published: 01.02.2019
• ISSN: 0352-9045; 2232-6979
• DOI: 10.33180/InfMIDEM2018.406

Cholinesterase inhibitors are widely used as pesticides, as chemical warfare agents and as drugs to treat symptoms of Alzheimer’s disease. Therefore, it is a high need to develop methods for their detection which are fast, sensitive, and reliable. This paper reports a preliminary work in the development of an electrochemical biosensor based on acetylcholinesterase (AChE) which is constructed by immobilization layers – cysteamine/glutaraldehyde/AChE on thin layer gold electrode for detection of cholinesterase inhibitors. Eserine (physostigmine) was used as a test inhibitor. The enzyme immobilization efficacy was evaluated by measuring activity of immobilized enzyme via Ellman’s method. The enzyme activity of the initial reduction of 33% in five days remained after that stable for at least one week. Chronoamperometric response to substrate acetylthiocholine chloride (ATCl) was assumed to follow Michaelis-Menten kinetics. After exposure biosensor to 25 mM eserine for 10 min, 70% inhibition of enzyme was detected. Reactivation factor of inhibited AChE was determined as 0.016 min-1.