Nanotechnology: UV light triggers chemical clean-up

A degradable nanoparticle system that absorbs pollutants from soil and water and then clump together if exposed to UV light is described in a paper published in Nature Communications this week. The platform offers a new approach for environmental clean-up by combining the high-absorption dynamics of nanoparticles with the ease of removal of bulk materials.

Exposure to waste chemicals is associated with increased risk of developing many disorders including cancer and diabetes. Nanoparticles that can bind or degrade pollutants offer a solution to the high prevalence of contaminated waters and soils; however, there are concerns about the formation of potentially toxic secondary products and the persistence of the nanomaterial in the environment. Given the unknown risks that this technology may carry, it is important to find effective ways to remove the nanomaterial from the environment following treatment.

Robert Langer and colleagues have now developed nanoparticles that bind and extract chemicals from contaminated water and soils. Once treated with ultraviolet light the nanoparticles shed their external layer and aggregate into lumps enriched with the pollutant, which can be easily separated and removed. This allows the use of highly active materials for pollutant extraction, without the risk of the nanomaterials persisting in the environment after use. Preliminary experiments using wastewater, thermal printing paper and contaminated soil suggests that this treatment can be successful without generating any toxic by-products.