Heterogeneity in susceptibility of viruses with different structures to various reactive oxygen species: Kinetics and biological mechanisms

Waterborne viruses have caused outbreaks of related diseases and threaten human health, and advanced oxidation processes (AOPs), as clean and efficient technologies, have received widespread attention for their excellent performance in inactivating viruses. However, heterogeneity in susceptibility of structurally distinct viruses to various reactive oxygen species (ROS) is unclear. This study first measured the heterogeneity in inactivation kinetics and biological mechanisms of four typical viral surrogates (MS2, phi6, phix174, and T4) to various ROS by visible light catalysis. Notably, the second-order inactivation rate constants of four viruses by hydroxyl radicals (·OH), singlet oxygen (¹O₂), and superoxide radicals (·O₂ ^-) were quite different: 10⁹-10¹⁰, 10⁷-10⁸, and about 10⁵ ​M^-1 ​s^-1, respectively. The susceptibility of four viruses to ROS varied significantly, in the order of phi6 ​> ​MS2 ​> ​phix174 ​> ​T4. More importantly, ¹O₂ can better oxidize capsid proteins. ·O₂ ^--induced RNA damage was significantly greater than that to the DNA genome, indicating that RNA viruses are more susceptible. ·OH can strongly inactivate the four structurally distinct viruses. Furthermore, the resistance of the ROS-inactivated virus to environmental interference was assessed in detail. This study advanced the understanding of heterogeneity in susceptibility of structurally distinct viruses to various ROS and provided a valuable theoretical basis for the application of AOPs in water disinfection.