Near-infrared-IIb probe affords ultrahigh contrast inflammation imaging.

Deep tissue imaging in the near-infrared II (NIR-II) window with significantly reduced tissue autofluorescence and scattering provides an important modality to visualize various biological events. Current commercially used contrast agents in the near-infrared spectrum suffer from severe photobleaching, high tissue scattering, and background signals, hampering high-quality bioimaging, particularly in small animals. Here, we applied a NIR-IIb quantum dot (QD) probe with greatly suppressed photon scattering and zero autofluorescence to map inflammatory processes.