Free Radicals Generated in Perfluorocarbon-Water (Liquid-Liquid) Interfacial Contact Electrification and Their Application in Cancer Therapy

Electron transfer during solid-liquid contact electrification has been demonstrated to produce reactive oxygen species (ROS) such as hydroxyl radicals ((OH)-O-center dot) and superoxide anion radicals (O-center dot(2)-). Here, we show that such a process also occurs in liquid-liquid contact electrification. By preparing perfluorocarbon nanoemulsions to construct a perfluorocarbon-water "liquid-liquid" interface, we confirmed that electrons were transferred from water to perfluorocarbon in ultrasonication-induced high-frequency liquid-liquid contact to produce (OH)-O-center dot and O-center dot(2)-. The produced ROS could be applied to ablate tumors by triggering large-scale immunogenic cell death in tumor cells, promoting dendritic cell maturation and macrophage polarization, ultimately activating T cell-mediated antitumor immune response. Importantly, the raw material for producing (OH)-O-center dot is water, so the tumor therapy is not limited by the endogenous substances (O-2, H2O2, etc.) in the tumor microenvironment. This work provides new perspectives for elucidating the mechanism of generation of free radicals in liquid-liquid contact and provides an excellent tumor therapeutic modality.