Design and Synthesis of Triphenylphosphonium Functionalized Nanoparticle Probe for Mitochondria Targeting and Imaging

Although various nanoparticle based cellular imaging probes are reported as alternatives for conventional molecular probes, the development of nanoparticle based subcellular imaging probes is challenging. Here we report inorganic nanoparticle based fluorescent probes of 30-40 nm hydrodynamic diameter that can target and label mitochondia. Nanoprobe has pH responsive polyacrylate shell with both anionic and cationic surface charge and functionalized with triphenylphosphonium group. Optimized surface chemistry offers high cellular uptake via predominate caveolae mediated endocytosis, and triphenylphosphonium group traffics them to mitochondria. This concept of surface chemistry can be extended to different nanoparticles and for development of other subcellular imaging nanoprobes.