Near-IR absorbing J-aggregates of a phenanthrene-fused BODIPY as a highly efficient photothermal nanoagent.

A phenanthrene-[b]-fused BODIPY exhibited well-defined J-aggregation behavior in both pure hydrocarbon solution and aqueous solution. The highly stable J-aggregates showed narrowed and largely red-shifted absorption with λmax of 840 nm and enhanced molar absorption coefficients (271 000 M-1 cm-1). Encapsulation of J-aggregates within a micellar nanocapsule resulted in nanoparticles that demonstrated good biocompatibility, excellent photothermal stability, high photothermal conversion ability (η ∼ 46.9%) and an effective phototoxicity (IC50 ∼ 2 μg mL-1 in HeLa cells) under 808 nm laser irradiation.