A shield of graphene can help particles destroy antibiotic-resistant bacteria and free-floating antibiotic resistance genes in wastewater treatment plants.
This new strategy was developed at Rice University and dupped the "wrap, trap and zap," according to Phys.org.
Rice environmental scientist Pedro Alvarez and Yalei Zhang, a professor of environmental engineering at Tongji University, Shanghai, introduced microspheres wrapped in graphene oxide in the Elsevier journal Water Research.
Alvarez and his partners in the Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT) are working towards tackling the antibiotic-resistant "superbugs" since first discovering them in wastewater treatment plants in 2013.
"Superbugs are known to breed in wastewater treatment plants and release extracellular antibiotic resistance genes (ARGs) when they are killed as the effluent is disinfected," said Alvarez. "These ARGs are then discharged and may transform indigenous bacteria in the receiving environment, which become resistome reservoirs.
According to Alvarez, the team’s idea would minimize the discharge of extracellular ARGs and mitigate dissemination of antibiotic resistance from wastewater treatment plants.
The Rice lab showed its spheres, with cores of bismuth, oxygen and carbon wrapped with nitrogen-doped graphene oxide, inactivated multidrug-resistant E.coli bacteria and degraded plasmid-encoded antibiotic-resistant genes in secondary wastewater effluent, according to Phys.org. The spheres did so by producing three times the amount of reactive oxygen species (ROS) compared to the spheres alone.
"Wrapping improved bacterial affinity for the microspheres through enhanced hydrophobic interaction between the bacterial surface and the shell," said co-lead author Pingfeng Yu, postdoctoral research associate at Rice's Brown School of Engineering. "This mitigated ROS dilution and scavenging by background constituents and facilitated immediate capture and degradation of the released ARGs."