TY  - JOUR
A1  - Tang, Jing
A1  - Werchmeister, Rebecka Maria Larsen
A1  - Preda, Loredana
A1  - Huang, Wei
A1  - Zheng, Zhiyong
A1  - Leimkühler, Silke
A1  - Wollenberger, Ulla
A1  - Xiao, Xinxin
A1  - Engelbrekt, Christian
A1  - Ulstrup, Jens
A1  - Zhang, Jingdong
T1  - Three-dimensional sulfite oxidase bioanodes based on graphene functionalized carbon paper for sulfite/O-2 biofuel cells
T2  - ACS catalysis
N2  - We have developed a three-dimensional (3D) graphene electrode suitable for the immobilization of human sulfite oxidase (hSO), which catalyzes the electrochemical oxidation of sulfite via direct electron transfer (DET). The electrode is fabricated by drop-casting graphene-polyethylenimine (G-P) composites on carbon papers (CPs) precoated with graphene oxide (GO). The negatively charged hSO can be adsorbed electrostatically on the positively charged matrix (G-P) on CP electrodes coated with GO (CPG), with a proper orientation for accelerated DET. Notably, further electrochemical reduction of G-P on CPG electrodes leads to a 9-fold increase of the saturation catalytic current density (j(m)) for sulfite oxidation reaching 24.4 +/- 0.3 mu A to cm(-2), the highest value among reported DET-based hSO bioelectrodes. The increased electron transfer rate plays a dominating role in the enhancement of direct enzymatic current because of the improved electric contact of hSO with the electrode, The optimized hSO bioelectrode shows a significant catalytic rate (k(cat): 25.6 +/- 0.3 s(-1)) and efficiency (k(cat)/K-m: 0.231 +/- 0.003 s(-1) mu M-1) compared to the reported hSO bioelectrodes. The assembly of the hSO bioanode and a commercial platinum biocathode allows the construction of sulfite/O-2 enzymatic biofuel cells (EBFCs) with flowing fuels. The optimized EBFC displays an open-circuit voltage (OCV) of 0.64 +/- 0.01 V and a maximum power density of 61 +/- 6 mu W cm(-2) (122 +/- 12 mW m(-3)) at 30 degrees C, which exceeds the best reported value by more than 6 times.
KW  - enzymatic biofuel cell
KW  - reduced graphene oxide
KW  - sulfite oxidase
KW  - carbon paper
KW  - direct electron transfer
Y1  - 2019
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/48921
SN  - 2155-5435
VL  - 9
IS  - 7
SP  - 6543
EP  - 6554
PB  - American Chemical Society
CY  - Washington
ER  -