Highly Sensitive Near-Infrared Imaging of Peroxynitrite Fluxes in Inflammation Progress

Inflammation is an important protection reaction in living organisms associated with many diseases. Since peroxynitrite (ONOO–) is engaged in the inflammatory processes, illustrating the key nexus between ONOO– and inflammation is significant. Due to the lack of sensitive ONOO– in vivo detection methods, the research still remains at its infancy. Herein, a highly sensitive NIR fluorescence probe DDAO-PN for in vivo detection of ONOO– in inflammation progress was reported. The probe responded to ONOO– with significant NIR fluorescence enhancement at 657 nm (84-fold) within 30 s in solution. Intracellular imaging of exogenous ONOO– with the probe demonstrated a 68-fold fluorescence increase (F/F0). Impressively, the probe can in vivo detect ONOO– fluxes in LPS-induced rear leg inflammation with a 4.0-fold fluorescence increase and LPS-induced peritonitis with an 8.0-fold fluorescence increase The remarkable fluorescence enhancement and quick response enabled real-time tracking of in vivo ONOO– with a large signal-to-noise (S/N) ratio. These results clearly denoted that DDAO-PN was able to be a NIR fluorescence probe for in vivo detection and high-fidelity imaging of ONOO– with high sensitivity and will boost the research of inflammation-related diseases.