Biofuel Cells Tila Hidalgo, Alief ISD
Chris Skinner, El Campo ISD
Zhilei Chen, PhD, Artie McFerrin Department of Chemical Engineering
Texas A&M University
Chemical Engineering
• Working with Dongli Guan, PhD• Electrochemistry using reagents
available in and compatible to biological systems.
Biofuel Cells• Redox Reactions- transfer of electrons• Fuel Cell- parts of the reaction are split into the
anode and cathode so that electrons are forced to travel.
• Reagents such as oxygen and glucose produce products that are not harmful such as water while generating free electrons.
Zebda et al 2011
The Research Question
• How can we make a biofuel cell generate sufficient power and longevity?
Why?
• Useful in various biomedical implants.
http://whoinvented.org/wp-content/uploads/2010/11/pacemaker1.jpg
The Research Objective
• To improve power and longevity of the fuel cell.• Current Issues
• Not a lot of power generated• Poor connections • Loss of enzyme from the fuel cell
Engineering a new protein
• Recombinant DNA is used to create an enzyme that will both catalyze the needed reaction and attach to the gel cathode and anode.
• The hope is that this will address the issues with the fuel cell.
Plasmids
• Small circular pieces of bacterial DNA.
http://www.biologie.uni-regensburg.de/Experimentierlabor/Experimente/Plasmid%20Isolierung/plasmid2.gif
Recombinant DNA
• DNA for the desired protein is identified, and cut out with restriction enzymes.
• Plasmid DNA is cut with the same restriction enzymes.
• The pieces are put together with an enzyme called ligase to create a new plasmid.
http://explorebio.wikispaces.com/file/view/sticky_ends.jpg/204841238/sticky_ends.jpg
http://biologyjunction.com/plasmid.gif
Transformation
• Newly engineered plasmid is then put into E. coli through a process called transformation.
• Transformed E. coli is then grown and induced to make the newly engineered enzyme.
• The protein is then harvested, purified and tested in the biofuel cell.
Protein Purification
• Once harvested, the proteins must be purified, or isolated
• During the engineering of the protein, it was "tagged" to make isolation easier
• The solution containing the protein is poured through a filter system.
Purification continued
• The protein is eluted from the filter using a buffer that has a higher affinity for the molecule
• The collected protein solution undergoes electrophoresis to demonstrate its purity
Construct a Fuel Cell
•Mix enzyme with Multi-walled carbon nanotubes (MWNT’s)
•Fix enzyme to electrodes•Argarose + MWNT + enzyme
Adhere to electrode
Measure Voltage
Summary
• Biofuel cells have great potential for real world application.
• Addressing issues with current models of biofuel cells by engineering proteins will provide low cost, high yield, green technology for use in living organisms.
Acknowledgements
• TAMU E3 program• National Science Foundation • Nuclear Power Institute• Dr. Chen and Dr. Guan
Citation Zebda, Abdelkader, Gondran, Chantal, Le Goff, Alan, Holziger, Michael, Cinquin, Phlippe,
Consiner, Serge. Mediatorless high-power glucose biofuel cells based on compressed carbon nanotube- enzyme electrodes. Nature Communications. 2011. 10: 1038.