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 devel-opment 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 fluo-rescence 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 (I628/I0), and excellent selectivity towards ONOO- over other analytes as well as a good linear relationship was observed between the I628/I0 and the ONOO- concentration range 0-1 mu M, 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.