Copper Sulfide Perfluorocarbon Nanodroplets as Clinically Relevant Photoacoustic/Ultrasound Imaging Agents.

We have developed laser-activated perfluorocarbon nanodroplets containing copper sulfide nanoparticles (CuS NPs) for contrast-enhanced ultrasound and photoacoustic imaging. As potential clinical contrast agents, CuS NPs have favorable properties including biocompatibility, biodegradability, and enhance contrast in photoacoustic images at clinically relevant depths. However, CuS NPs are not efficient optical absorbers when compared to plasmonic nanoparticles and therefore, contrast enhancement with CuS NPs is limited, requiring high concentrations to generate images with sufficient signal-to-noise ratio.