Satisfying Bacterium’s Appetite for Gold Nanoclusters turned it into Hybrid Artificial Photosynthesis System
Nanotechnologies have shown great potential in harnessing solar energy for feeding the worldwide demand for renewable and sustainable energy. To this end, researchers and engineers all over the world are looking for improving efficiency of photosynthetic biohybrid systems (PBSs). Combining nanotechnology with biosynthetic pathways of certain microorganisms may lead to innovation in the current biohybrid systems and further help boosting the performance of affordable resources fuels.
A team of researchers from University of California, Berkeley, U.S. developed several models to test this and found that the bacterium Moorella thermoacetica has astounding appetite for gold nanoclusters, which can be harnessed for solar fuel production. The researchers placed light-absorbing gold nanoclusters intracellular to satisfy the urge of this CO2-hungry bacterium. This leads to higher production of chemical products used in solar fuel cells.
The study specifics and the findings are detailed in an article published on October 1 in the peer reviewed journal Nature Nanotechnology.
Nanoclusters made of 22 Gold Atoms improved Quantum Efficiency of System
In the initial model developed by one of the researchers, nanoparticles made of cadmium sulfide (CdS) was attached to the exterior of the bacteria membrane. The researcher found that nanoparticles in the hybrid model absorbed visible light, generated electrons, and triggered reactions that led to the production of acetate, an useful chemical for solar fuel cells. However, the model wasn’t useful since the vital electrons generated had reduced the quantum efficiency of the system when the nanoparticles were placed intracellular to the bacterium.
To overcome this constraint, the researchers used nanoclusters made of 22 gold atoms that could boost the production of acetate by improving the CO2 reduction pathway. Luckily, the researchers found that the nanoclusters didn’t disrupt the biological system of the bacterium. This was confirmed using imaging technology at UC Berkeley’s Molecular Imaging Center. The researchers are now focused on making the biohybrid system more cost-effective and durable.