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.