A reversible calix[4]arene armed phenolphthalein based fluorescent probe for the detection of Zn2+ and an application in living cells.

A reversible and easy assembled fluorescent sensor based on calix[4]arene and phenolphthalein (C4P) was developed for selective zinc ion (Zn2+ ) sensing in aqueous samples. The probe C4P demonstrated high selective and sensitive detection towards Zn2+ over other competitive metal ions. Interaction of Zn2+ with a solution of C4P resulted in a considerable increment in emission intensity at 440 nm (λex  = 365 nm) due to the suppression of photoinduced electron transfer (PET) process and the restriction of C=N isomerization. The binding constant (Ka ) of C4P with Zn2+ was calculated to be 4.50 × 1011  M-2 and also the limit of detection of C4P for Zn2+ was as low as 0.108 µM (at 10-7  M level). Moreover, the fluorescence imaging in the human colon cancer cells suggested that C4P had great potential to be used to examine Zn2+ in vivo.

Anthracene excimer-based "turn on" fluorescent sensor for Cr(3+) and Fe(3+) ions: Its application to living cells.

A novel anthracene based fluorescent probe containing benzothiazole group (BFA) was designed and synthesized. The cation binding properties of BFA were studied in the presence of various cations. Both UV-vis and fluorescence spectroscopic studies indicated that BFA was highly sensitive and selective toward trivalent cations (Cr(3+) and Fe(3+)), while there was no response to monovalent, divalent cations and also Al(3+) ion. The interaction of BFA with Cr(3+) and Fe(3+) caused a significant enhancement in emission intensity due to the combination of a unique anthracenyl static excimer formation, the restricted C=N isomerization and the suppression of highly efficient photoinduced electron transfer (PET) process. The detection limits of BFA for Cr(3+) and Fe(3+) were 0.46 and 0.45µM, which presented a pronounced sensitivity toward Cr(3+) and Fe(3+), respectively. Also, possible utilization of BFA as bio-imaging fluorescent probe to detect Cr(3+) and Fe(3+) in human prostate cancer cell lines was observed by confocal fluorescence microscopy.

Fluorogenic recognition of Zn(2+), Al(3+) and F(-) ions by a new multi-analyte chemosensor based bisphenol A-quinoline.

A new available multi-analyte fluorescent sensor based on a bisphenol A-quinoline conjugate (BFQ) was synthesized in two facile steps and was characterized systematically. BFQ exhibited an effectively selective and sensitive recognition toward Zn(2+)and Al(3+) cations in EtOH-H2O (v/v = 9/1) over other cations and F(-) anion in CH3CN over other anions with remarkably enhanced fluorescent intensities. According to the quantum yield (Φ) measurements, BFQ-Zn(2+), BFQ-Al(3+) and BFQ-F(-) complexes showed 16, 22 and 30 times higher Φ values than BFQ, respectively. The complexation properties of BFQ with Zn(2+), Al(3+) and F(-) ions were also examined by (1)H NMR titration experiments.

A novel colorimetric and fluorescent sensor based on calix[4]arene possessing triphenylamine units.

A novel colorimetric and fluorometric calix[4]arene probe (CTP) bearing triphenylamine units was synthesized in good yield and characterized by combination of (1)H, (13)C, APT, COSY, FTIR, HRMS, and UV-vis spectral data. Ion-binding studies of CTP were investigated in acetonitrile with a wide range of cations and anions and the recognition process was monitored by luminescence, UV-vis and (1)H NMR spectral changes. CTP exhibited naked eye detection for Hg(2+) ion. Also it showed a significant fluorescence quenching towards F(-) ion.

Complexation properties and synthesis of a novel Schiff base with triphenylene nucleus.

We presented the synthesis of a novel Schiff base and its complexation properties with some transition metal ions in this work. For this, the 2,3,4,6,7,10,11 hexahydroxytriphenylene (HHTP) as starting material was synthesized according to known procedure. Moreover, the 2-((2-chloroethylimino)methyl) phenol material was prepared with reaction of salicylaldehyde and 2-chloroethylamine hydrochloride. To give the 2,3,4,6,7,10,11-hexakis(salicyliminoethoxy)triphenylene (HSE-TP) as a novel Schiff base, the HHTP were treated with 2-((2-chloroethylimino)methyl)phenol in acetone media. Complexation properties of this Schiff base were investigated towards Ni(II), Cu(II), Co(II), Zn(II), Pd(II) and Cd(II) as transition metals. The structures of these new compounds (ligand and complexes) were characterized with FT-IR, magnetic susceptibility measurement, thermal methods (TGA), (1)H NMR and elemental analyses.