A FRET-based ratiometric fluorescent probe for hydrogen polysulfide detection in living cells and zebrafish

Hydrogen polysulfide (H2Sn, n > 1) is an important active sulfur molecule (RSS) in organisms, which have been considered to be involved in redox signaling and cytoprotective processes. In this work, in order to quickly and accurately detect H2Sn in biosystems, 2-fluoro-5-nitrobenzoic ester was used as the response moiety for H2Sn, and the FRET strategy was adopted to effectively connect the donor (6-hydroxy-2-naphthoic acid) and acceptor (4-substituted-1,8-naphthalimide) to construct a new ratiometric H2Sn flu-orescent probe NPNA-H2Sn. NPNA-H2Sn exhibited a more than ti 8.0-fold ratio enhancement towards H2Sn at I450/I526 and a very high sensitivity with a very low detection limit of 40.3 nM. Impressive, NPNA-H2Sn was further used for fluorescence imaging of H2Sn in living cells and zebrafish, which showed high-clear ratiometric images. Therefore, we have demonstrated that NPNA-H2Sn could be applied for ratiometric images of endogenous H2Sn in living biosystems and provide a powerful molecular tool for evaluating the physiological and pathological functions of H2Sn. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

A new ratiometric fluorescent probe NPNA-H2Sn was developed with high sensitivity and advantage of colorimetric imaging for rapid and accurate detection of H2Sn. The probe can be used for evaluating the physiological and pathological functions of H2Sn, providing a powerful molecular tool for research in living biosystems.