An Imidazo[1,5-a]pyridine Benzopyrylium-Based NIR Fluorescent Probe with Ultra-Large Stokes Shifts for Monitoring SO2

Abstract

A mitochondria-targeted NIR probe based on the FRET mechanism was developed. It shows ultra-large Stokes shifts (460 nm) and emission shifts (285 nm). Furthermore, we also realized the imaging of SO2 in living SKOV-3 cells, zebrafish and living mice which may be useful for understanding the biological roles of SO2 in mitochondria and in vivo.

Imidazopyridine Family: Versatile and Promising Heterocyclic Skeletons for Different Applications

“…Moreover, many studies have been conducted regarding the application of chemosensors based on imidazo[1,5- a ]pyridines for the quantification of hydrogen sulfide [ 62 ] and hydrogen polysulfides [ 175 ], sulfur dioxide [ 177 , 180 ], hypochlorous acid [ 181 , 182 , 183 ], and metal ions such as Cd 2+ and Zn 2+ [ 184 ], Hg 2+ [ 47 , 185 ], and Cu 2+ [ 170 , 186 ].…”

An endoplasmic reticulum-targeted fluorescent probe for ratiometric tracking of endogenous SO2 derivatives

“…[16][17][18][19] Recently, the design mechanisms for functional fluorescent probes have been mainly based on intramolecular charge transfer (ICT), [20][21][22][23] through-bond energy transfer (TBET), 24,25 Fo ¨rster resonance energy transfer (FRET), 26,27 photo-induced electron transfer (PET) 28,29 and excited-state intramolecular proton transfer (ESIPT). 30,31 Although FRET-based ratiometric probes with various superiorities such as large Stokes shift, and facile design and synthesis were developed, [32][33][34][35][36] ER-targeted FRET-based probes for the monitoring of HSO 3 À /SO 3 2À are rarely developed (Table S1,…”

I2/H2O2 mediated synthesis and photophysical properties of imidazole-fused heterocycles via [4+1] cyclization approach

“…The optoelectronic features of imidazo [1,5-a]pyridines and benzimidazoles are remarkable since the molecules based on them display unique photophysical properties with quantum yields ranging from moderate to high, huge Stokes shift, and good stability under the tested conditions. Specifically, applications of imidazo [1,5a]pyridines and benzimidazoles in organic optoelectronic materials include organic light-emitting devices (OLEDs) [30,31], nonlinear optic materials (NLOs) [32,33], photosensitizers based on organic metal complexes [34,35], fluorescence cell imaging [36,37], organic fluorescent probes [38][39][40][41][42], sensors and emitters for confocal microscopy [17] and so on. In the design of fluorescent dyes and fluorescent materials, introducing strong electron donors and extending the molecular π-conjugated system has been proven to be an efficient strategy to lengthen emission wavelengths as well as Stokes shifts [43][44][45][46][47][48] Besides, fluorescent dyes with electron donors can retain a relatively high fluorescent quantum yield, which is determined by the gap between frontier orbitals [49][50][51][52][53].…”