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 lambda(max) 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 (eta similar to 46.9%) and an effective phototoxicity (IC50 similar to 2 mu g mL(-1) in HeLa cells) under 808 nm laser irradiation.