Provided herein are nanobubbles designed for use in ultrasound-mediated ablation of cancer cells. The nanobubbles undergo ultrasound-mediated cavitation at an ablation threshold which is significantly decreased, relative to standard ultrasound-mediated treatment of cancer cells. In exemplary embodiments, the nanobubbles comprise an amphiphilic ABC triblock copolymer, wherein block A comprises a hydrophilic polymer, block B comprises a crosslinking polymer, and block C comprises a hydrophobic copolymer comprising (i) methyl methacrylate (MMA) and (ii) a fluorinated monomer, wherein the fluorinated monomer is present in the hydrophobic copolymer of block C at 25 mole percent or less. Related treatment and diagnostic methods, as well as materials relating to the nanobubbles are provided herein. Methods of making a random copolymer are furthermore provided herein.