Localization matters: a nuclear targeting two-photon absorption iridium complex in photodynamic therapy.

We present a two-photon (2P, 800 nm) PDT cyclometalated Iridium(iii) complex (Ir-Es) that targets the intracellular nucleus. The complex is capable of migrating sequentially from the nucleus to mitochondria and inducing dual-damage under light exposure. This study suggests that with minor modification of the terminal moieties of complexes, their final intracellular destinations and PDT efficiency can be significantly impacted.