The present disclosure relates to compositions and methods of killing cells in vitro or in vivo. In particular examples, the method includes contacting a cell having a cell surface protein with a therapeutically effective amount of an antibody-IR700 molecule, wherein the antibody specifically binds to the cell surface protein. In particular examples the antibody recognizes a tumor-specific antigen on the surface of a tumor cell. The cell is subsequently irradiated, such as at a wavelength of 660 to 740 nm at a dose of at least 1 J cm−2, thereby killing the cell. Also provided are wearable devices that include an article of clothing, jewelry, or covering; and an NIR LED incorporated into the article, which can be used with the disclosed methods.