| Abstract [eng] |
Doctoral dissertation of Ieva Sakinyte is an interdisciplinary scientific work intended for creation and investigation of highly effective reagentless enzymatic systems based on sp2 hybridized carbonaceous materials. In this study five GOPs, TRGrO and three TRGO fractions were synthesized using graphite oxidation, thermal reduction of graphite oxide (GrO) and by newly proposed thermal reduction of graphene oxide (GO). These materials were characterized by TGA, AFM, BET, SEM, XRD, Raman spectroscopy, titrimetric and elemental analysis. The GOPs, TRGrO and TRGO fractions were applicable for design of reagentless amperometric systems based on pyrroloquinoline quinone dependent glucose dehydrogenase from Acinetobacter calcoaceticus sp., urease from Canavalia ensiformis or D-fructose dehydrogenase from Gluconobacter industrius (FDH). The examination of kinetic characteristics of systems allowed to select TRGO fractions as the most appropriate materials for reagentless amperometric carbamide and D-fructose biosensors design. The efficiencies of these carbamide biosensors were ten times higher compared to that of GOPs based biosensors while the sensitivity of D-fructose biosensors was the same order as for the other mediated processes based systems. The proposed biosensor based on urease and TRGO2 was applicable for precise detection of carbamide in dialysate while biosensor based on FDH immobilized on TRGO1 was applied for precise detection of D-tagatose in D-galactose bioconversion reaction mixture. |
