We have examined changes in single-walled carbon nanotubes (SWNT) optical signals upon addition of recombinant [FeFe] hydrogenases from Clostridium acetobutylicum or Chlamydomonas reinhardtii. We found evidence that novel and stable charge-transfer complexes are formed only under conditions of hydrogenase catalytic turnover. Formation of the complex sensitizes the nanotubes to the proton-to-hydrogen redox half-reaction. Thus, the experimental potential can be altered by changing the pH or molecular hydrogen concentration. In the presence of molecular hydrogen, hydrogenase mediates electron injection into the conduction band of semiconducting SWNT, which was observed as a quenching of the photoluminescence signals. Here, we will present recent Raman studies, which revealed that SWNTs in a complex with hydrogenase may undergo either oxidation or reduction, depending on the electronic structure of the SWNT and the oxidation state of the enzyme. In addition, we will describe our efforts to prepare stable, solubilized SWNT/hydrogenase complexes in the absence of detergent. This work shows that SWNT/hydrogenase complexes have potential applications as a component of an energy conversion device.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2008: Life Sciences, Medicine & Bio Materials – Technical Proceedings of the 2008 NSTI Nanotechnology Conference and Trade Show, Volume 2
Published: June 1, 2008
Pages: 289 - 292
Industry sectors: Advanced Materials & Manufacturing | Medical & Biotech
Topics: Biomaterials, Materials Characterization & Imaging