A novel reversible fluorescent probe for Cu²⁺ and S²⁻ ions and imaging in living cells

Abstract

A novel fluorescent probe TSOC (thiazole salicylaldehyde oxazole chlorinated) was synthesized based on benzothiazole conjugated olefinic bond with salicylicaldehyde unit as fluorophore and a phenyl oxazole unit as bonding unit. The probe could reversibly detect of Cu2+ and S2− over other common ions with longer emission and large stokes shift in an aqueous solution at pH 7.3 (DMSO-Hepes, v/v, 5:1, 10 mM). The bonding mechanism was supported through the titration experiment of fluorescence and absorption spectroscopy, 1H-NMR titration, HR-MS and DFT calculations. Moreover, the probe further exhibited good cell permeability and were successfully used to visualize Cu2+ and S2− in living cells.

Activity-Based Fluorescent Probes for Hydrogen Sulfide and Related Reactive Sulfur Species

“…894 Sun and Xu reported the Cu 2+ benzothiazolium 884 (TSOC), which provides a red-shifted turn-on response to H 2 S at 600 nm. 895 This probe showed good selectivity for H 2 S over competing anions and was demonstrated to respond to exogenous H 2 S in SHSY5Y cells. Expanding to carbazole-based systems, Liu and Jiang reported 885 (CAH), which provided a turn-on response at 425 nm with moderate activation by GSH, Cys, and Hcy, and was used to develop paper sensors for H 2 S. 896 Fewer examples of Cu 2+ coordination for H 2 S reporting involve primarily oxygen-based coordination spheres.…”

“…Wang reported the NBD-Cu 2+ complex 883 , which provided a turn-on response to H 2 S at 540 nm with good selectivity over other anions and also Cys, GSH, and DTT and was further used to measure H 2 S in different water samples . Sun and Xu reported the Cu 2+ benzothiazolium 884 (TSOC), which provides a red-shifted turn-on response to H 2 S at 600 nm . This probe showed good selectivity for H 2 S over competing anions and was demonstrated to respond to exogenous H 2 S in SHSY5Y cells.…”

Small-Molecule Fluorescent Probe for Detection of Sulfite

“…In the last decade, fluorescent probes have been used for the detection of various anions [20], such as ClO − , Cl − , NO 2 − , F − , CN − , S 2− , Br − , etc [21][22][23][24][25][26][27]. In 2010, Choi et al reported the first fluorescent probe for sulfite [28].…”

A novel conjugated polymer fluorescence probe for the detection of copper ions in aqueous media

“…In addition, several conjugated polymers (CPs) have been designed and applied in the detection of heavy metal ions [24,25], such as amino acids [26], enzymes [27], and DNA [28]. Superior to small molecular probes, CPs, such as poly (p-phenylene vinylene) [29,30], polythiophenes [31,32], and polyfluorene [33][34][35], can respond to minor perturbations and stimuli because of their excellent photoelectric conversion properties and signal amplification [36][37][38][39], resulting in a significant improvement in the sensitivity and detection limit. However, the high preparation cost and harsh reaction conditions limit the widespread application of CPs.…”