Fluorescence imaging of SO2 derivatives in Daphnia magna with a mitochondria-targeted two-photon ratiometric fluorescent probe

Sulfur dioxide (SO2), one of the reactive sulfur species (RSS), plays significant roles in various physiology and pathological processes. Excessive inhalation of SO2 will be conducive to the occurrence of respiratory diseases, neurological disorders and cardiovascular diseases, even lung cancer. Hence, it's vital to develop efficient methods for real-time monitoring of SO2 in vivo. In this work, a two-photon ratiometric fluorescent probe TP-SO2 was proposed based on Michael addition mechanism, which showed a 143-fold enhancement of fluorescence intensity ratio (F483 JF600,) toward SO2 with outstanding sensitivity (DL 0.161 M), rapid response (35s) and high selectivity. Probe TP-SO2 showed good cell membrane permeability and localized in mitochondria. More importantly, to the best of our knowledge, it is the first time that the probe TP-SO2 was used for visualizing exogenous SO2 derivative changes in Daphnia magna through two-photon fluorescence microscopy, which is of great importance for biological research. (C) 2017 Elsevier B.V. All rights reserved.