Watch magnetic nanobots grab pollutants from water
S. Himmelstein | April 06, 2022A nanorobotic approach to removing heavy metal contaminants from water is being advanced by researchers from the Czech Republic.
Temperature-responsive magnetic nanorobots were engineered to bond with heavy metals under certain circumstances and release them under others. The 200 nm wide nanobots were assembled with a temperature-sensitive pluronic tri-block copolymer as an attractant and iron oxide to allow for control via magnetic fields. The material bonds with heavy metals in cold water environments and when placed in warm water, the bonds relax so that metals separate from the material.
In the field, nanobots placed in cool water systems would disperse and collect, or bind, any heavy metals encountered. The devices could then be directed with a magnetic field to a separate site where the water could be heated, releasing the metals.
The nanobots scatter (a) and (b) begin accumulating pollutant payloads. The devices then aggregate (c) and release the collected pollutants (d). Source: Martin Pumera et al.
The maximum pickup efficiency of toxic metal (arsenic) and pesticide (atrazine) by the temperature-responsive tools was 65.2% and 61.5% when placed in contaminated tap and river water samples. The disposal process was observed to reach equilibrium after 100 minutes, with arsenic efficiency of 48% and atrazine efficiency of 38.4%. Research results reported in Nature Communications also demonstrate that the dynamic pickup efficiency of both pollutants by these reusable nanorobots is enhanced two-fold over a static system.
According to researchers from the University of Chemistry and Technology Prague and Academy of Sciences of the Czech Republic, inclusion of high molecular weight or graft pluronic copolymers in the nano/micromotors could further improve the pickup capacity by enhancing functional groups and adsorption sites.