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

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

SpinBioAnode (“Nature’s spin-flipping machine: design of the semiconductor-free biophotoanode”) tackles a key weakness of today’s photovoltaic and photo-bioelectrochemical technologies: they depend on scarce, hard-to-recycle semiconductors and lose most of the absorbed photon energy as heat. Bacterial reaction-centre (bRC) proteins already convert light into charge with near-unity quantum yield, yet conventional biohybrid devices extract electrons only after ~70 % of that energy is dissipated, constraining the open-circuit voltage (OCV) to ≈0.5 V. SpinBioAnode exploits an alternative, long-lived triplet state that lies ~1.0 eV above the ground state, theoretically doubling the attainable OCV and paving the way for biodegradable, metal-free solar electrodes. The project’s overall goal is to build and validate the first energy-efficient, semiconductor-free biophotoanode in which electrons are harvested directly from the triplet state and delivered to an external circuit through a viologen-based redox-polymer hydrogel that also scavenges oxygen and protects the protein matrix. To reach this goal the work is structured around three research objectives: RO1 – To construct a working biophotoanode utilizing the primary donor triplet as the electron source state RO2 – To identify photocurrent limitations within the constructed biophotoanode RO3 – To optimize photocurrent generation by rationally addressing the identified bottlenecks Pathway to impact Scientific: deliver the first mechanistic picture of utilization pf a triplet electron transfer in a biohybrid photovoltaic device and provide open kinetic models and spectroelectrochemical protocols for the field. Technological: establish a blueprint for sustainable photoanodes that can be utilized to power in situ biocatalysis, biosensors etc. Industrial & economic: offer a route to photovoltaic coatings made entirely from earth-abundant, biodegradable components, lowering material costs and supply-risk barriers for EU SMEs. Societal & environmental: advance European Green Deal goals by reducing reliance on critical raw materials, easing end-of-life recycling and opening photovoltaic niches where biodegradability and low-waste manufacturing are paramount (e.g., off-grid micro-power in developing regions). By rewiring nature’s spin-flipping machinery into a protective redox-polymer framework, SpinBioAnode aims to demonstrate a new class of clean, scalable optoelectronic devices and to lay rigorous scientific foundations for their future commercialisation.

Data: CORDIS, © European Union