Gold-Iron bimetallic nanoparticles as multimodal contrast agents

In a one-step approach to obtain a multimodal bimetallic nanoparticle, different from standard chemical methods process, using laser ablation synthesis in solution (LASiS) of a gold-iron alloy target (73% Au- 27% Fe) surface of the particles, and their optical and magnetic characteristics were analysed using XPS, UV-Visible and SERS instruments. In a second series of experiments, bimetallic nanoparticles were tested for CT, SERS and MRI analysis, yielding good results in all the three fields. In vivo analysis on mice was also carried out, showing a good retention in tumour sites. The bioocompatibility and MRI performance of the nanoparticles were compared to those of a commercially available MRI contrast agent, showing equivalent biocompatibility and comparable results. With the added benefit of the CT functionality, these nanoparticles show great promise as multimodal agents