Materials and methods for synthesizing magnetic core/gold shell nanoparticles and magneto-plasmonic nanostars are provided. Formulations comprising nanoparticles optionally bound to or co-loaded with a therapeutic agent encapsulated within liposomes are provided. A method for treating diseases (e.g., brain diseases) in a subject by administering to the subject a formulation comprising the nanoparticle formulation is also provided. Further, a method is provided for imaging a target site of a subject following the administering of the nanoparticle formulations.