LAUSR

Microbubbles stabilized by particle surfactants (i.e. Pickering bubbles) have better thermodynamic stability compared to microbubbles stabilized by small molecules as a result of steric hindrance against coalescence, higher diffusion resistance, and higher particle desorption energy. In addition, the use of particles to stabilize microbubbles that are typically used as an ultrasound (US) contrast agent can also introduce photoacoustic (PA) properties, thus enabling a highly effective dual-modality ultrasound and photoacoustic contrast agent. Here we report the use of partially reduced and functionalized graphene oxide as sole surfactant to stabilize perfluorocarbon gas bubbles in the preparation of a dual-modality US and PA agent, with high contrast in both imaging modes and without the need for small molecule or polymer additives. This approach offers an increase in loading of PA agent without destabilization and increased thickness of the microbubble shell compared to traditional systems in which focus on adding a PA agent to existing microbubble formulations.