Nanomaterials are capable of generating reactive oxygen species (ROS) due to defect-induced electronic interactions with oxygen and water stimulated by environmental and structural factors (e.g., photonic energy, band edge energy, and morphology) resulting in excellent pro-oxidant activity of nanomaterials. The pro-oxidant activities are demonstrated by the antibacterial activity of nanomaterials under different environmental conditions (e.g., varying light levels). This review examines research related to the pro-oxidant activity of metallic, non-metallic, metal oxide nanoparticles (NPs), and their composites.
Moreover, there is a scavenging phenomenon for nanomaterials that manifests itself as inhibition of ROS (i.e., anti-oxidant activity) which is also dependent on the electronic property of the nanomaterials, which is examined. These nanomaterials experience a crossover between pro-oxidant and anti-oxidant activities depending on concentration, morphology, etc., which offers the nanomaterials potential for application in cancer therapy and inflammatory disease treatment.