Direct bioelectrocatalytic oxidation of glucose by gluconobacter oxydans membrane fractions in PEDOT:PSS/TEG-modified biosensors

Abstract

Recent years have witnessed an ever-increasing interest in developing electrochemical biosensors based on direct electron transfer-type bioelectrocatalysis. Thiswork investigates the bioelectrocatalytic oxidation of glucose bymembrane fractions of Gluconobacter oxydans cells on screen-printed electrodes modifiedwith thermally expanded graphite and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Electrooxidation of glucose was shown to occur without the presence of electron transport mediators. Chronoamperometric and cyclic voltametric characteristics showed an increase of anodic currents at electrode potentials of 0–500 mV relative to the reference electrode (Ag/AgCl). The direct electron transfer effect was observed for non-modified PEDOT:PSS as well as for PEDOT: PSS linked with crosslinkers and conductive fillers such as polyethylene glycol diglycidyl or dimethyl sulfoxide. Bioelectrodes with this composite can be successfully used in fast reagent-free glucose biosensors.