Bimodal Visualization of Endogenous Nitric Oxide in Lysosomes with A Two-Photon Iridium(III) Phosphorescent Probe.

Author(s) Wu, W.; Guan, R.; Liao, X.; Yan, X.; Rees, T.W.; Ji, L.N.; Chao, H.
Journal Anal Chem
Date Published 2019 Jul 11
Abstract

Nitric oxide (NO) is a fundamental signaling molecule that shows complex effects on the catabolic autophagy process, which is closely linked with lysosomal function. However, owing to the dynamic transformation of the components of the highly heterogeneous lysosomes and the complicated microenvironment in lysosomes , it is hard to explore the interaction between NO and lysosomes. In this study, a new lysosome-targeted, pH-independent and two-photon phos-phorescent iridium(III) complex, Ir-BPDA, has been investigated for endogenous NO detection and imaging. The rational design of the probe, as the addition of the morpholine moieties and the substitution of a benzyl group in the amino group in Ir-BPDA, facilitates its accumulation in lysosomes and makes the reaction product with NO, Ir-BPDA-NO, insuscepti-ble in its phosphorescence intensity and lifetime against pH changes (pH 4~10), well suited for lysosomal NO detection (pH 4~6). Furthermore, Ir-BPDA exhibits a fast and 50-fold response to NO in phosphorescence intensity and a two-photon cross-section as high as 60 GM after the reaction, as well as a notably increased phosphorescence lifetime from 200.1 ns to 619.6 ns. Thus, accompanied by its photostability, Ir-BPDA enabled the detection of NO in the lipopolysac-charide-stimulated macrophages and zebrafish model, revealing the endogenous lysosomal NO distribution during inflammation in vivo by means of both TPM and PLIM imaging techniques.

DOI 10.1021/acs.analchem.9b02415
ISSN 1520-6882
Citation Wu W, Guan R, Liao X, Yan X, Rees TW, Ji L-, et al. Bimodal Visualization of Endogenous Nitric Oxide in Lysosomes with A Two-Photon Iridium(III) Phosphorescent Probe. Anal Chem. 2019.