Evaluation Properties of Bioelectrodes Based on Carbon Superfine Materials Containing Model Microorganisms Gluconobacter

摘要

We have studied the properties of a bioelectrode formed by the immobilization of Gluconobacter oxydans bacterial cells on carbon superfine materials (CSMs). We use three types of CSMs (as adopted by the working classification CSM 1C3) with different carbonization rates. The bioelectrode is formed by covering the surface of the CSM suspension of bacteria in a chitosan gel. The properties of samples are evaluated by measuring the physiological state of the bacteria immobilized: (a) recording the intensity of cellular respiration, (b) for measuring the charge transport characteristics of electrode (bioelectrocatalysis), and (c) by measuring the electrode impedance. Measurements (b) and (c) are made on two and three-electrode circuits in the oxidation of ethanol in the presence of 2,6-dichlorophenol bacteria electron transport mediator. For CSMs 1 and 2 the electron transport by the oxidation of the substrate is not registered, while for CSM 3 the current generation occurs. The resistance of CSM 3 bioelectrode is below the resistance of CSMs 1 and 2 both before (39.6 k/cm~2 for CSM 3, 630 /cm~2 for CSM 2, and 1329 /cm~2 for CSM 1) and after the addition of the substrate (2.9 k/cm~2 for CSM 3, 45 k/cm~2 for CSM 2, and 58 k/cm~2 for CSM 1). The bioelectrode made of CSM 3 has a capacitance of 196 F/cm~2greater than two orders of magnitude of the bioelectrode capacity of CSMs 1 and 2 (0.51 and 0.58 F/cm~2, respectively). It is important to further study the properties of the CSM class of materials, which are promising as the basis of mechanically flexible electrodes with controlled parameters.