Biofuel Cell Based on Carbon Fiber Electrodes Functionalized with Graphene Nanosheets

Abstract

Carbon fiber electrodes were electrochemically modified with graphene nanosheets in situ deposited in the 3D-structure, characterized by field emission scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman scattering methods. The graphenemodified electrodes were further functionalized with PQQ-dependent glucose dehydrogenase and laccase and used for assembling a biofuel cell operating in the presence of oxygen and glucose "fuel". The paper represents novel approach to the production of graphene-functionalized electrodes and their use in biofuel cells, potentially applicable in implantable bioelectronics devices.

A Biofuel Cell Based on Biocatalytic Reactions of Glucose on Both Anode and Cathode Electrodes

“…Electrode Preparation : Carbon paper composed of carbon fibers, CF, (Spectracarb TM 2050 L‐1050; Fuel Cell Store, TX) was used as the electrode material. The graphene nano‐flakes were produced on the carbon fibers using the published procedure ,. Hemin and MB were adsorbed on the graphene‐modified electrodes due to their π‐π staking.…”

“…Also, the use of rough or porous electrode materials can be helpful for increasing the load of the biocatalytic system on the electrode, thus increasing current density generated by the electrodes. Based on our recent studies ,, carbon fiber electrodes with electrochemically produced graphene flakes represent excellent choice for electrodes used in biofuel cells, demonstrating superior properties in terms of electron transfer rate constants and electrode area, comparing with many other commonly used electrodes. Thus, we used the carbon fiber electrodes with the graphene flakes as the conductive support for the biocatalytic electrodes in the present study (see Figures SI‐1 and SI‐2 and technical details on the electrode preparation in the Supporting Information).…”

“…The generated voltage and particularly current were significantly smaller than those obtained with the graphene‐functionalized electrodes. The difference was mostly explained by the higher surface area of the graphene‐electrodes ,. Also, the voltage‐current output was rapidly decreasing when carbon fiber electrodes without graphene have been used due to a weaker adsorption of MB and hemin on graphite electrodes.…”

“…The cathodic reaction was based on the intermediate formation of H 2 O 2 being reduced by hemin. The presence of graphene facilitated the electrochemical processes due to the higher electrode area and possibly faster interfacial electron transfer ,. The present design of the potentially implantable biofuel cell is particularly attracting because of its simplicity.…”

Bioelectrocatalytic Electrodes Modified with PQQ‐Glucose Dehydrogenase‐Calmodulin Chimera Switchable by Peptide Signals: Pathway to Generic Bioelectronic Systems Controlled by Biomolecular Inputs

“…This approach has been applied recently to construct pyrroloquinoline quinone‐dependent glucose dehydrogenase (PQQ‐GDH) (typical quinoprotein) fused with calmodulin (CaM) unit responsive to Ca 2+ cations ,. Since PQQ‐GDH enzyme is capable of direct (non‐mediated) electron transfer to various electrodes (particularly based on carbon nanotubes, “buckypaper”,, or on graphene‐functionalized electrodes), the chimeric PQQ‐GDH‐CaM enzyme was previously immobilized on a graphene‐modified carbon fiber electrode to yield the Ca 2+ ‐dependent electrochemical system . The constructed electrode was activated for glucose oxidation only in the presence of Ca 2+ cations and inhibited in their absence.…”