Nature’s spin-flipping machine: design of the semiconductor-free biophotoanode

Current challenges of humankind in coping with raising energy needs make it necessary to look for alternative technologies for harvesting renewable energy.

One of the strategies is to construct biophotovoltaics that directly exploits naturally abundant and highly efficient photosynthetic proteins as photoactive components. My goal within SpinBioAnode is to construct the first generation of energy-efficient semiconductor-free biophotoanodes.

To do so, I will design, assemble, characterize, and optimize a biohybrid photoanode consisting of a photosynthetic reaction center interfaced with electrode materials via an electron-conductive immobilization matrix.

SpinBioAnode comprises a unique approach for solar energy conversion that hijacks a highly energetic triplet state formed by a spontaneous electron spin flip in purple bacteria photosynthetic reaction centers.

This spin flip is biologically unfavorable, but potentially lucrative for biohybrid applications that require large open circuit potentials and high solar energy conversion efficiencies above 1% which to date, have not been achieved using state-of-the-art biophotovoltaics.

I will apply a strongly interdisciplinary approach for characterization of the photoanode prototype using a combination of spectroscopic, electroanalytical and modelling methods. This will be achieved by collaboration within a network of physicists, chemists, and biologists. The characterization results will be utilized in the feedback loop workflow to optimize the constructed biophotoanode.

Utilization of biologically unfavorable pathways within protein, opened by means of biohybrid approaches, is still an unexplored area in biophotoelectrodes design and the outcome of the SpinBioAnode project will serve as a blueprint in the wider field of light energy conversion in a road towards reaching Sustainable Development Goals such as affordable and clean energy.