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By the incorporation of coumarin fluorophores within the benzyldihydrazone moiety and by carefully adjusting the redox potential of the fluorophore and its excited state energy, one of the brightest Cu2+-binding sensors in aqueous media was achieved and could be used for the detection of Cu2+in living cells. [ABSTRACT FROM AUTHOR]

A novel Ru-based phosphorescent probe was designed for the detection of thiophenol using 2,4-dinitrobenzenesulfonate as a sensing unit. The probe exhibited a remarkable off–on type of phosphorescent response towards thiophenol over other commonly encountered metal ions, anions, and aliphatic thiols. The probe was able to work in pure water medium and instantaneously responded to thiophenol with a 36-fold enhancement in 30 seconds. This probe displayed a large Stokes shift (216 nm) and long luminescence lifetime, and the detection limit reached as low as 30 nM. Moreover, detection of thiophenol is based on the thiol-induced cleavage of a sulfonamide linkage to generate a strongly phosphorescent species, Ru-NH2, which showed obvious AIEE activity. Furthermore, the potential for practical applications of this probe has been successfully demonstrated in monitoring thiophenol in real water samples and on test paper. [ABSTRACT FROM AUTHOR]

Effective discrimination of cysteine (Cys) from biothiols and other amino acids has gained increasing attention due to the essential roles of this molecule in biological systems. In this work, we report a new strategy for the detection of Cys in aqueous media and live cells using a simple Cu2+ ensemble (L–Cu2+). A coumarin–salicylaldehyde hydrazone fluorescent ligand (L) was initially synthesized and well characterized. L features high affinity towards Cu2+ (Ka = 1.995 × 106 M−1), accompanied by effective quenching of fluorescence in HEPES buffer. The in situ generated chemosensing ensemble, L–Cu2+, is able to specifically respond to Cys over other biothiols and amino acids through a displacement approach. As a result, a remarkable recovery of fluorescence and UV-vis absorption spectra can be observed. L–Cu2+ showed high selectivity and sensitivity towards Cys. The detection limit is estimated to be 15 nM. Using L–Cu2+ as the fluorescent probe, imaging of Cys in live A549 cells was successfully demonstrated. [ABSTRACT FROM AUTHOR]