EAGER: A Hybrid Photosynthetic Electron Transport Chain Based on Graphene Oxide

Cuny Medgar Evers College, Brooklyn NY

Investigators

Abstract

1260073 Vittadello Several approaches for biological and biomimetic energy conversion systems have been proposed. In particular, the possibility of using photosynthesis to produce hydrogen from biological resources is attractive, and both natural microorganisms and semi-artificial devices are being investigated within various national and international programs. The approaches of semi-artificial device research being followed are aimed at a photoelectrochemical system based on PSII and PSI, which are natural photosystems, and hydrogenase. The original model, proposed in 1979, entailed the use of particles floating in solution in the presence of redox mediators. New strategies proposed by the research team of Professor Michele Vittadello of CUNY Medgar Evers College and Professor Paul Falkowski of Rutgers University involve the immobilization of PSII and PSI CCs (core complexes) and hydrogenases onto electrodic surfaces. So far, no one has published a full working device using isolated core complexes. Vittadello and Falkowski propose to demonstrate the possibility by assembling a viable photosynthetic hybrid system for water splitting based on graphene oxide (GO), core complexes of natural photosystems PSII and PSI, and Pt as a catalyst. Single-layered GO provides an ideal chemical ?canvas? for the self-assembly of photosynthetic proteins. The residual oxygen-containing chemical species include hydroxyl, carboxyl, epoxy, and ketonic functional groups concentrated at the edges of graphene quantum islands. The degree of oxidation can be used to control electron/hole transport properties. Although preliminary results for the PSI-GO and PSII-GO have been attained, the basis for this EAGER proposal is the attempt to demonstrate that photoinduced vectorial electron transfer is possible in triads comprised of PSII CCs, GO, and PSI CCs in a direct or facilitated fashion, giving rise to a supramolecular hybrid electron-transport chain with minimized overpotentials, on the model of the natural photosynthetic Z-scheme. The investigators are well qualified for conducting this project given their background knowledge in photosynthesis, electrochemistry, biophysics, biochemistry, materials science and engineering. The research team includes Senior Research Associate Kamil Woronowicz and is in an excellent position to expand the collaborative effort in semi-artificial photosynthesis for hydrogen generation. The investigation of GO-protein interactions is highly transformational for bionanotechnologies with potential applications in multi-enzyme catalysis for fuel production and chemical synthesis, and protein purification for drug development. The successful proof-of-concept will lay the foundation for further studies. The vibrancy of the topic will help leverage the ongoing effort of the investigators in the STEM educational area, through the unique institutional expertise available at Medgar Evers College and at the Rutgers Energy Institute.