Compositions and methods used in the non-invasive detection and/or treatment of hypoxic tissues in vivo are described. Compositions including microbubbles functionalized with one or more hypoxia targeting agents and one or more therapeutic compounds, methods of preparing the functionalized microbubbles, and methods of using the functionalized microbubbles for diagnostic and/or therapeutic applications are described, including a method for selectively determining the amount of vascular hypoxia occurring in a tissue.
