(a) Silica-coated gold nanorods with enhanced thermal stability. Reproduced with permission from[69]. (b) cTEM image of a dual ultrasound and photoacoustic contrast agent. Perfluorocarbon droplets loaded with silver nanotriangles. Reproduced with permission from Wilson K, Homan K, Emelianov S. Synthesis of a dual contrast agent for ultrasound and photoacoustic imaging. In: Samuel A, Ramesh R, editors. Reporters, Markers, Dyes, Nanoparticles, and Molecular Probes for Biomedical Applications II; 2010; San Francisco, CA, USA; 2010. p. 75760M [53]. (b) Silica-coated gold nanorods with enhanced thermal stability. Reproduced with permission from Chen YS, Frey W, Kim S, et al. Enhanced thermal stability of silica-coated gold nanorods for photoacoustic imaging and image-guided therapy. Opt Express 2010 Apr 26;18(9):8867–78. [69].