Bacterial Cellulose as a Matrix for Microorganisms in Bioelectrocatalytic Systems

Bacterial cellulose (BC) produced by the Komagateibacter sucrofermentas VKPM B-11267 bacteria was used as a carrier for immobilization of acetic acid bacteria Gluconobacter oxydans in amperometric biosensors. The bioreceptor was formed on the surface of a screen-printed graphite electrode modified with thermally expanded graphite (TEG) or on the surface of a porous three-dimensional material, nickel foam (NF). Structural features of these materials contributed to the creation of a firm contact between the electrode material and the surface of the BC on which the bacterial cells were immobilized. Scanning electron microscopy showed that bacteria not only sorb on the surface of BC but are also able to penetrate the inner volume of the film. Conductivity of both types of biosensors was studied using impedance spectroscopy and the resistance of the graphite electrode was shown to decrease by three orders of magnitude after its surface is modified with TEG. Bioelectrodes containing BC were used in the construction of an amperometric biosensor for glucose determination. The sensitivity of the biosensor was 3 μA/mM × cm 2 . Thus, BC in combination with TEG and NF can be used to create three-dimensional electrodes of bioelectrocatalytical devices.