Multimodal imaging based on complementary detection principles has great potential for improving the accuracy of tumor diagnosis. Fe₃O₄ core/Au shell nanoparticles (Fe₃O₄@Au NPs) can be used as an effective multimodal contrast agent due to combining the advantageous and highly complementary features of the Fe₃O₄ core and gold shell. In the present work, we have developed a novel Fe₃O₄@Au NP based probe for targeting and multimodal imaging of cancer cells. The prepared Fe₃O₄@Au NPs have been characterized by transmission electron microscopy (TEM), visible spectra and SERS. The potential use of the prepared Fe₃O₄@Au NPs as a multimodal contrast probe for magnetic resonance imaging (MRI), microwave-induced thermoacoustic imaging and photoacoustic imaging was then evaluated. Importantly, when conjugated with a cancer cell targeted molecular and fluorescent dye, the Fe₃O₄@Au NPs could be internalized by the corresponding cancer cells selectively and sensitively, and fluorescence imaging was realized at the same time. The bio-modified Fe₃O₄@Au NPs incorporating multiple functionalities into one single nano-structured system can be effectively used for targeting and multimodal imaging of cancer cells simultaneously.