Breast cancer, as the most common type of cancer among women, achieves around 1.7 million newly diagnosed patients every year. It is still challenged to fully remove the breast cancer tissues and the metastasis and recurrence cause the vast majority death due to the breast cancer. Thus, novel strategies that can selectively remove all cancer tissues and prevent recurrence are highly needed and urgent. This proposal is focused on the development of a simple All-in-One multi-modes therapeutic nanoparticle for eliminating both primary tumor residues and metastatic breast cancer. Phototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), utilizes photos as the energy source to produce either abundant reactive oxygen species (ROS) or generate local high temperature to ablate cancer cells. With the development of laser system and photosensitzers, phototherapy has been in clinical translations for several types of cancer treatment. Phototherapy is ideal for primary tumor treatment especially during the sugery with the guidance of imaging ability. This will help eliminating the primary residues after the surgery. However, phototherapy is not feasible for the treatment of metastatic tumor nodules because the requirement of laser source for triggering therapeutic effect. Chemodynamic therapy (CDT) takes advantages of abundant hydrogen peroxide and acidic tumor microenvironment to generate highly toxic hydroxyl radicals to kill cancer cells. CDT is intrinsically selective to tumor tissues compared with the normal tissues due to its requirements of acid environment, high level of hydrogen peroxide, and Fenton reaction catalyst such as Fe2+. The long-term goal of our research is to develop a novel multifunctional nanoplatform for the treatment of breast cancer. The central hypothesis is: The combination of phototherapy and CDT by our proposed all-in-one nanoparticle will eliminate both the primary breast tumor and metastatic breast cancer tissues by phototherapy and CDT, respectively.