Inhibition of immobilized acetylcholinesterase by aflatoxin B1 in a potentiometric biosensor

Abstract

To identify a type of inhibition of immobilized acetylcholinesterase by aflatoxin B1. Methods. A bioselective element of the potentiometric biosensor was created using acetylcholinesterase, which was covalently immobilized on the surface of the pH-FET sensor by glutaraldehyde crosslinking with bovine serum albumin. Results. Optimal conditions for the potentiometric biosensor operation such as pH-optimum of the enzyme action and its inhibition were defined. An apparent Michaelis constant, as well as a maximum initial reaction rate of immobilized acetylcholinesterase as a part of the biosensor were determined. The type of reversible inhibition of immobilized acetylcholinesterase by aflatoxin B1 in potentiometric biosensor was identified by using a new graphical "degree of inhibition" method and the obtained result was confirmed with one of the traditional methods, such as the Lineweaver-Burk plot. Conclusions. This study helps to understand the mechanisms of enzyme inhibition in biosensors and brings the biosensor implementation closer. K e y w o r d s: biosensor, immobilized acetylcholinesterase, type of inhibition, aflatoxin B1, potentiometric transducer.

Practical application of electrochemical enzyme biosensors

“…Electrochemical enzyme biosensors based on acetylcholinesterase and pH-sensitive fiels effect-transistors have been developed for aflatoxin B1 detection, and their laboratory prototypes were fabricated and thoroughly tested for cereal samples [16][17][18][19].…”

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“…Electrochemical enzyme biosensors based on acetylcholinesterase and pH-sensitive fiels effect-transistors have been developed for aflatoxin B1 detection, and their laboratory prototypes were fabricated and thoroughly tested for cereal samples [16][17][18][19].…”

Flow-Through Acetylcholinesterase Sensor with Replaceable Enzyme Reactor

“…Due to a wide variety of species exerting the anticholinesterase effect, AChE biosensors were proposed as indicators of general pollution of the environment [ 17 ] and for detection of heavy metals [ 18 ], surfactants [ 19 ], fluorides [ 20 ] and organic solvents [ 21 , 22 ] exerting a non-specific inhibitory effect. Recently, AChE biosensors were also successfully utilized for the determination of reversible inhibitors, e.g., anti-dementia drugs [ 23 , 24 ] and aflatoxins [ 25 , 26 ].…”