A facile method for synthesis of copper-cysteamine nanoparticles and study of ROS production for cancer treatment Nil Pandey, Lalit Chudal, Jonathan Phan, Liangwu Lin, Omar Johnson, Meiying Xing, Jianping Liu, Haibin Li, Xuejing Huang, Yang Shu and Wei Chen Abstract Copper-cysteamine (Cu-Cy) is a novel sensitizer that can be excited by ultraviolet (UV) light, microwave (MW), ultrasound, and X-ray to generate highly toxic reactive oxygen species (ROS) for cancer cell destruction.