Reviewed by Lexie CornerJan 30 2025
Scientists from The University of Manchester have developed a new material designed to reduce water pollution caused by persistent contaminants, such as pharmaceutical and personal care product residues, that accumulate in rivers and lakes. Their findings were published in Cell Reports Physical Science.
Water pollution remains a significant environmental challenge. Many everyday products, including cosmetics and medications, leave behind chemical residues that do not fully degrade. These pollutants frequently enter aquatic ecosystems, posing risks to human health, wildlife, and plant life.
The study introduces a novel approach based on a molecular structure known as a metal-organic cage (MOC). These nanoscale cages act as molecular traps, selectively capturing and retaining hazardous chemicals commonly found in wastewater.
While MOCs have been widely explored for chemical and gas capture, previous studies have primarily focused on their behavior in organic solvents, where their properties differ significantly from those in aqueous environments. Demonstrating their ability to sequester known wastewater contaminants in water represents a key step toward developing practical water purification applications.
This new MOC technology could provide a valuable tool to help clean up water systems and prevent pollutants from entering our ecosystem.
Jack Wright, Study Lead Researcher, The University of Manchester
Jack Wright said, “Being able to use MOCs in water is a fascinating development. We know how valuable MOCs are for capturing unwanted substances, but until now, researchers have not been able to apply them to real-world water systems.”
Many harmful chemicals are difficult to remove from water, and with water pollution becoming a global crisis, this new MOC technology could provide a valuable tool to help clean up water systems and prevent pollutants from entering our ecosystem, particularly in rivers and lakes near urban or industrial areas where wastewater discharge is most common.
Jack Wright, Study Lead Researcher, The University of Manchester
The MOCs have a hollow pyramidal structure, consisting of metal ions linked by organic ligands. These cages are designed to trap specific molecules, such as pollutants or gases, within their central cavities.
The new MOC structure incorporates sulfonate functional groups to enhance compatibility with aqueous environments, including natural water systems and wastewater treatment facilities. These modifications improve water solubility and facilitate pollutant capture under real-world conditions.
The trapping mechanism relies on hydrophobic binding, a natural phenomenon in which contaminant molecules preferentially adhere to the interior of the cage rather than remaining in the surrounding water. This selectivity enables the material to capture and retain pollutants even in complex aqueous environments.
One of the real strengths of this method is its flexibility. The approach we have developed could be used to design other water-soluble MOCs with different sizes or properties. This opens the door to many future applications, including cleaning up different kinds of pollutants, development of green catalysts, or even development of drug delivery strategies.
Dr. Imogen Riddell, Ph.D. Supervisor and Researcher, The University of Manchester
The researchers aim to expand the range of water-soluble MOCs to capture a broader spectrum of contaminants. Additionally, they are developing methods to efficiently recycle the cages, ensuring their long-term viability as sustainable water purification materials.
Journal Reference:
Wright, J. D., et al. (2025) Encapsulation of hydrophobic pollutants within a large water-soluble [Fe4L6]4− cage. Cell Reports Physical Science. doi.org/10.1016/j.xcrp.2025.102404.