Spectrophotomeric Assay of Aflatoxin B1 Using Acetylcholinesterase Immobilized on Standard Microplates

Abstract

Aflatoxins are a group of hepatotoxic secondary metabolites produced by molds Aspergillus. During inappropriate storage or processing of food and beverages, aflatoxins can be distributed and become a serious health problem. Disparate analytical techniques were prepared for the assay in the past. Here, a method based on inhibition of enzyme acetylcholinesterase (AChE) is performed allowing fast and simple prove of aflatoxins presence. For the assay purposes, AChE was immobilized on standard polystyrene microplates using gelatin as a stabilizing substance. Both free and immobilized AChEs were used and compared one to each other. Immobilization protocol was optimized and interference of organic solvents such as methanol was tested. For the immobilized AChE, limit of detection 2.75 ppb for aflatoxin B1 was received. The immobilized AChE kept full activity at least one month. Suitability of the assay for a practical performance is considered.

Keywords:

• Acetylcholinesterase
• Aflatoxin
• Aspergillus
• Biosensor
• Butyrylcholinesterase
• Ellman method
• Mycotoxin

Acknowledgments

A long-term organization development plan 1011 (Faculty of Military Health Sciences, University of Defense, Czech Republic) is gratefully acknowledged.