University of Colorado, Boulder researchers have developed nanobio-hybrid organisms capable of taking carbon dioxide from the air and converting it into products such as biodegradable plastic, petrol, ammonia and biodiesel.
The researchers used light-activated quantum dots, which are tiny semiconductors similar to those used in television sets, to activate particular enzymes within microbial cells.
Specially-tailored quantum dots were fired into the cells of common microbial species found in soil. After this, exposure to even small amounts of indirect sunlight activated the microbes’ CO2 appetite, without the need for any source of energy or food to carry out the biochemical conversions.
Different combinations of dots and light produce different products. For example, green wavelengths cause the bacteria to consume CO2 and nitrogen to produce ammonia while red wavelengths make the microbes consume CO2 to produce plastic. The microbes lie dormant in water and release their resulting product to the surface, where it can be skimmed off and harvested for manufacturing.
The researchers believe that the process will be able to operate at scale. They found that, even when the microbial factories were activated consistently for hours at a time, they showed few signs of exhaustion or depletion. But they acknowledge that they are “just getting started with the synthetic applications”.