A robust high selectivity fluorescence turn-on nanoprobe for peroxynitrite detection in inflammatory cells and mice.

Changed levels of intracellular peroxynitrite anion (ONOO) are closely related to the occurrence and development of inflammation. Specific imaging of ONOO at sites of inflammation can be of great significance not only for inflammation diagnosis but also for obtaining a deeper understanding of the role of ONOO in inflammation. Therefore, there is an urgent need for constructing some reliable tools to study the relationship between ONOO and inflammation in biosystems. In this work, we developed a robust high selectivity fluorescence turn-on nanoprobe (Rhb-ONOO) for inflammation-targeted imaging of ONOO. The Rhb-ONOO was obtained by self-assembly of amphiphilic Rhb-ONOO, which was constructed by the condensation reaction of the hydrophobic, ONOO-response and deep red-emitting fluorophore (Rhb) with hydrophilic biopolymer glycol chitosan (GC). Rhb-ONOO showed rapid response towards ONOO during 60 s, high sensitivity with 19-fold enhancement of fluorescence intensity ratio (I/I), and excellent selectivity towards ONOO over other analytes as well as a good linear relationship was observed between the I/I and the ONOO concentration range 0-1 μM, with an excellent limit of detection (LOD) of 33 nM. Impressively, it was successfully employed Rhb-ONOO for ONOO imaging in living inflammatory cells and drug-induced inflammatory mice, illustrating nanoprobe Rhb-ONOO has excellent potential for further study ONOO-related inflammatory diseases.