Title Reagentless D-tagatose biosensors based on the oriented immobilization of fructose dehydrogenase onto coated gold nanoparticles- or reduced graphene oxide-modified surfaces: application in a prototype bioreactor
Authors Šakinytė, Ieva ; Butkevičius, Marius ; Gurevičienė, Vidutė ; Stankevičiūtė, Jonita ; Meškys, Rolandas ; Razumienė, Julija
DOI 10.3390/bios11110466
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Is Part of Biosensors: Special Issue Electrochemistry and spectroscopy-based biosensors.. Basel : MDPI. 2021, vol. 11, iss. 11, art. no. 466, p. [1-15].. ISSN 2079-6374
Keywords [eng] bioelectrocatalysis ; Au nanoparticles ; thermally reduced graphene oxide ; direct electron transfer ; biosensors ; D-tagatose ; fructose dehydrogenase ; D-galactose bioconversion
Abstract [eng] As electrode nanomaterials, thermally reduced graphene oxide (TRGO) and modified gold nanoparticles (AuNPs) were used to design bioelectrocatalytic systems for reliable D-tagatose monitoring in a long-acting bioreactor where the valuable sweetener D-tagatose was enzymatically produced from a dairy by-product D-galactose. For this goal D-fructose dehydrogenase (FDH) from Gluconobacter industrius immobilized on these electrode nanomaterials by forming three amperometric biosensors: AuNPs coated with 4-mercaptobenzoic acid (AuNP/4-MBA/FDH) or AuNPs coated with 4-aminothiophenol (AuNP/PATP/FDH) monolayer, and a layer of TRGO on graphite (TRGO/FDH) were created. The immobilized FDH due to changes in conformation and spatial orientation onto proposed electrode surfaces catalyzes a direct D-tagatose oxidation reaction. The highest sensitivity for D-tagatose of 0.03 ± 0.002 μA mM−1cm−2 was achieved using TRGO/FDH. The TRGO/FDH was applied in a prototype bioreactor for the quantitative evaluation of bioconversion of D-galactose into D-tagatose by L-arabinose isomerase. The correlation coefficient between two independent analyses of the bioconversion mixture: spectrophotometric and by the biosensor was 0.9974. The investigation of selectivity showed that the biosensor was not active towards D-galactose as a substrate. Operational stability of the biosensor indicated that detection of D-tagatose could be performed during six hours without loss of sensitivity.
Published Basel : MDPI
Type Journal article
Language English
Publication date 2021
CC license CC license description