Application of enzyme field-effect transistors for determination of glucose concentrations in blood serum

Glucose-sensitive enzyme held effect transistors (ENFETs) modified by an ad ditional Naflon membrane have been developed and used for diluted blood sam ples analysis. The ENFET was used in the linear portion of the calibration curve up to 1.5 mM glucose in a model solution, which corresponds with up t o 60 mM glucose in the undiluted samples (dilution 1:40). The high linearit y of the Grans curve (factor of linearity is 1.03) obtained by the method o f standard additions indicates the high precision of analysis. Glucose conc entrations in different blood serum samples determined by ENFETs were compa red with those measured by the commercial analyzer 'Eksan-G' and colorimetr ic method ('Diagluc' enzymatic kit), and good correlation between these met hods was revealed. The high reproducibility and operational stability of th e biosensor developed were demonstrated. (C) 1999 Elsevier Science S.A. All rights reserved.