Synthesis of a near-infrared fluorescent probe and its application in imaging of MCF-7 cells.

IR-789, a novel near-infrared fluorescent probe, was designed, synthesized, and applied to living cells. The probe exhibited better response fluorescence characteristics than the only FDA-approved agent, indocyanine green. Cell experiments showed that the probe had high affinity and without apparent cytotoxicity. Fluorescent image experiments in living MCF-7 cells (human breast adenocarcinoma cell line) further demonstrated the potential applications of the probe in biological systems. The probe effectively prevented the influence of autofluorescence and native cellular species in biological systems. It also exhibited high sensitivity, good photostability, and excellent cell membrane permeability.