A completely water-soluble, high quantum yield blue-fluorescent benzimidazole derivative (AQ), containing a rigid benzimidazole-thiophene structure, was synthesized. Among 21 metal ions, the fluorescence ofAQwas selectively turned off by Cu2+to form anAQ-Cu2+ensemble. Thereafter, the fluorescence of theAQ-Cu2+ensemble was turned on by sulfide (S2-) with high selectivity and sensitivity in pure water solution. In comparison withAQ-Ag+andAQ-Hg2+ensembles,AQ-Cu2+was the only ensemble that was capable of detecting a sulfide anion. Also, the fluorescence intensity ofAQwas linearly proportional to the concentration of Cu2+and S2-. Both Cu2+and S2-were detected within a minutein vitro. Moreover,AQworked best in the pH range of 5-10 and had a limit of detection of 50 nM and 354 nM for Cu2+and S2-respectively. It was employed for the detection of sulfide in human lung cancer A549 cells with low cytotoxicity.
Scopus Subject Areas
- Inorganic Chemistry