SIMULTANEOUS DETERMINATION OF MALTOSE AND GLUCOSE USING A SCREEN-PRINTED ELECTRODE SYSTEM

A screen-printed sensor system consisting of a glucose oxidase (GOD) e lectrode and an amyloglucosidase/glucose oxidase (A/G) electrode was c onstructed to determine maltose and glucose simultaneously in a mixtur e. Sensor construction was optimised so that it contained 20 units of GOD/40 units of amyloglucosidase and 0.2 mM 1,1'-ferrocenedimethanol. These components were deposited onto a screen-printed carbon electrode and an outer membrane was printed from 3.5% hydroxyethyl cellulose (H EC) solution. The optimum pH was 4.8. The linear range of the system w as up to 40 mM glucose or 20 mmol/L maltose with coefficients of varia tion (CVs) ranging from 3.5% to 5.29%. The results obtained by using t he enzyme electrode system agreed well with those obtained by the Fehl ing titration method. When stored dry, especially at 4 degrees C, the enzyme electrodes showed good stability over four months. (C) 1998 Els evier Science S.A.