DEVELOPMENT OF AN AMPEROMETRIC BIOSENSOR FOR THE ACETYLCHOLINE DETERMINATION IN BIOLOGICAL SAMPLES

The work is devoted to the development of amperometric biosensor for the determination of acetylcholine in biological samples. In the work, two different variants of co-immobilization of choline oxidase and acetylcholinesterase were compared, and two-layer method of immobilization was selected (acetylcholinesterase-based membrane was deposited as the first layer, and choline oxidase-based membrane – as the second layer). Next, influence of the solution properties (buffer capacity, ionic strength, pH) on the biosensor analytical characteristics was studied. It was shown that the biosensor is characterized by good signal reproducibility and operational stability. Selectivity of the biosensor towards substances, which can be present in biological samples, was evaluated. Main analytical characteristics of the biosensor (sensitivity, linear range, limit of detection, noise, drift, reproducibility of responses) were determined. It was proven that the developed biosensor could be used for the determination of acetylcholine concentrations in biological samples.