The graphene shield helps the particles kill antibiotic-resistant bacteria and resistance genes in wastewater treatment plants. A new method for fighting bacteria is described in the “wrap, catch and kill” strategy developed at Rice University. Scientists from the Rice Environmental Research Laboratory and Tongji University in Shanghai have unveiled microspheres wrapped in graphene oxide and published their research in the journal Elsevier Water Research.
Scientists at the Research Center for Nanosystems for Water Treatment with Nanotechnology (NEWT) have been working to eradicate antibiotic-resistant superbugs since their first discovery in wastewater treatment plants in 2013.
Antibiotic-resistant bacteria are known to multiply in wastewater treatment plants and release extracellular antibiotic resistance (ARG) genes when they are killed during wastewater disinfection. These ARGs are then discharged and can transform native bacteria in the host environment. Scientists’ innovations will minimize the release of extracellular ARGs and therefore reduce the spread of antibiotic resistance in wastewater treatment plants.
Rice’s lab demonstrated its development. Special spheres for wastewater treatment with bismuth, oxygen, and carbon cores wrapped in graphene oxide.
The spheres in the graphene shell kill off unpleasant sinks by producing three times more reactive oxygen species (ROS) than spheres alone. The spheres themselves are photocatalysts that form ROS when exposed to light. Laboratory tests have shown that wrapping the spheres minimizes the ability of ROS scavengers to limit their ability to disinfect the solution.
The researchers say nitrogen-doping the shells increases their ability to trap bacteria, giving the catalyst balls more time to kill them. The improved particles then immediately hijack and degrade the resistant genes released by dead bacteria before they pollute the wastewater.