BC/PEDOT:PSS/Graphene Conductive Composite As the Receptor Element for a Bacterial Biosensor

Тhe search for new materials with high conductivity and biocompatibility for use in biosensors is an important task. One promising material is bacterial cellulose (BC) due to its high surface area, high porosity, and biocompatibility. In this study, bacterial cellulose is modified with the PEDOT:PSS conductive gel and carbon nanomaterials to increase conductivity. Thermally expanded graphite/BC/PEDOT:PSS/graphene composition is used to immobilize Gluconobacter oxydans acetic-acid bacteria on the surface of a screen-printed carbon electrode. The effect of individual components of the composite on the catalytic activity of bacteria in the presence of 2,6-dichlorophenolindophenol redox mediator is studied. The addition of BC to the composition provides a higher stability of the electrode: the drop in signal within 35 days is 9%. A microbial biosensor based on TEG/PEDOT:PSS/Graphene/BC/G. oxydans composite show better sensitivity (36.4 µA mM–1 cm–2) and lower detection limit (0.005 mM) as well as the widest linear detection range (0.005–2 mM) compared to the other compositions. Thus, bacterial cellulose modified with conductive additives can be applied as a matrix for the immobilization of bacteria in microbial biosensors and microbial fuel cells.