Dudchenko O. Development and optimization of conductometric multibiosensor for determination of number of carbohydrates in foodstuffs.

Object: a change in solution conductivity due to enzymatic reactions in the bioselective membranes of biosensors for determination of glucose, sucrose, maltose, lactose and fructose. Aim: to develop enzymatic conductometric multibiosensor for simultaneous determination of glucose, sucrose, maltose, lactose, and biosensor for determination of fructose, and optimization of their analytical characteristics for analysis in foodstuffs. Methods: conductometry in differential mode; electrochemical impedance spectroscopy; HPLC. The procedure of testing the conductometric transducers to be used in biosensors was elaborated. The first laboratory prototype of conductometric biosensor for fructose determination with a linear range of 0.05 - 1.75 mM was created. The basic analytical characteristics of the developed multibiosensor for simultaneous determination of sucrose, glucose, maltose and lactose were studied and optimized to obtain required working parameters. Use of zeolite particles in the bioselective membrane was shown to enhance the process of enzymes immobilization on the transducer surface, and thus to improve the main analytical parameters of biosensor. The multibiosensor developed was used for analysis of sucrose and glucose in real samples of beverages and honey. A high correlation of the results of biosensor determination with those obtained by HPLC was demonstrated (R = 0.99).