Multifunctional nanoparticles are at the core of a growing field called theranostics that develops technologies physicians can use to diagnose and treat diseases in a single procedure. The major promise of theranostics is to bring together key stages of a medical treatment, such as the diagnosis and therapy, and thus to make a treatment shorter, safer and more efficient. Theranostic approaches require adequate tools with a high multi-functionality and selectivity. The initial phase of the development of theranostics has already revealed the two general challenges: lack of multifunctional methods and agents, and the lack of selectivity and specificity of available agents - that ultimately requires cell and molecular levels. Researchers have now developed a novel method based on gold nanoparticle-generated transient photothermal vapor nanobubbles, a structure they refer to as plasmonic nanobubbles.