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Acenaphthene imidazole ligand (AIMP) reacted with zinc acetate for the synthesis of Zn-AIMP complex which was used to detect pyrophosphate (PPi) ions in the environment as well as biotic systems based on the ligand cleavage method. The designed Zn-AIMP probe has greater fluorescence quenching response to PPi ions compared to other competitive ions and biothiols. Zn-AIMP probe shows the detection limit of 6 [mu]M in dimethyl sulfoxide with the binding constant (K.sub.b) value of 1.02 x 10.sup.4 M.sup.-1. Moreover, the probe possesses detection ability in the pH range from 4 to 10, which is also an optimum range for any biotic system., Author(s): Venkatachalam Kavitha [sup.1], Krishnamoorthy Chitra [sup.1], Asaithambi Gomathi [sup.1], Rajasekaran Dhivya [sup.1], Periasamy Viswanathamurthi [sup.1] Author Affiliations: (1) grid.412490.a, 0000 0004 0538 1156, Department of Chemistry, Periyar University, , [...]

A simple pyrene-based "turn-on" chemosensor bearing isonizide namely 3-(pyren-1-yl methylene) pentane-2,4-diyldene di(isonicotinohydrazide) (PMPD) was designed and synthesized for detecting Fe3+and Fe2+ ions in HEPES buffer solution at pH 7.4 (DMSO: H2O (1:9 v/v)) medium. The probe shows conducive selectivity for Fe2+ and Fe3+ ions over the other competitive metal cations. The detection limit was found to be 1.67 μM for Fe3+ and 2.02 μM for Fe2+. The recognition mechanism of PMPD towards Fe3+ and Fe2+ has been examined in detail by absorption, emission, and ESI-MS studies. Moreover, "turn-on" fluorescence behavior of the probe was used to track iron ions in living cells. [ABSTRACT FROM AUTHOR]

2,6‐bis((E)‐(2‐(benzo[d]thiazol‐2‐yl)hydrazono)methyl)‐4‐(4,5‐diphenyl‐1H‐imidazol‐2‐yl)phenol (PIS) conjugate has been designed as a selective fluorescent probe for zinc ion. The PIS exhibits selectivity towards Zn2+ among various ions in DMSO‐H2O (1:9) v/v 50 mM HEPES (4‐(2‐hydroxyethyl)‐1‐piperazineethanesulfonic acid) at pH=7.4. Moreover, the detection of PIS towards Zn2+ ion could be realized in "naked eye" with a color conversion from yellow to greenish yellow. The linear relationship between fluorescence intensity and Zn2+ ion concentration indicates that PIS can be used for quantification of Zn2+ ion. The PIS probe can be used in broad pH ranging from 4 to 9. The limit of detection (LOD) was found to be 0.52 nM for Zn2+ ion. The binding ratio and binding constant of PIS‐Zn2+ complex were determined and calculated as 1:1 and 2.36×106 M−1 according to Job′s plot and Benesi–Hildebrand equation, respectively. Furthermore, the PIS‐Zn2+ complex subsequently acted as a secondary fluorescent turn‐off probe for pyrophosphate (PPi) ion recognition among the other anions. To assess the real‐world efficacy of the PIS and PIS‐Zn2+ complex, they were evaluated by test paper strips. Likewise, the probe PIS and PIS‐Zn2+ complex were used as in vitro cell imaging probe, and successfully demonstrated as feasible bio‐marker as well. Diphenyl‐Imidazole based dipodal Schiff‐Base appended based probe (PIS) was designed and synthesized. PIS showed good selectivity towards Zn2+ion with 'turn‐on'fluorescence emission and PIS‐Zn2+ complex showed selective sensing towards pyrophosphate anion (PPi). The probe PIS and PIS‐Zn2+ complex could detect Zn2+ and PPi ions in live cells as well as in test paper strips. [ABSTRACT FROM AUTHOR]

A simple Schiff base probe PADP ((1,2-phenylenebis(azanylylidene)) bis(methanylylidene))bis(3-(diethylamino)phenol) was synthesized from 4-(diethylamino)salicylaldehyde and o-phenylenediamine and has been characterized using analytical and spectral methods. The emission spectrum of PADP Schiff base shows notable enhancement in the emission intensity at 500 nm in the presence of Al3+ in MeOH-H2O (1:9 v/v). On the other hand, other relevant metal ions did not influence considerably the emission spectrum of PADP. The detection limit and binding constant (Kb) of PADP towards Al3+ were found to be 0.104 µM and 3.0 × 106 M−1 from the fluorescence titration experiments. The 1:1 binding stoichiometry was further determined by Job's plot and ESI-MS spectroscopy. The MTT assay shows no or negligible toxic nature of probe and thus it was utilized in vitro cell imaging studies of Al3+ ions. The results show that the probe PADP could be useful to detect Al3+ in an aqueous medium. A simple non-toxic turn-on fluorescence receptor (PADP) was designed. The sensing performance of the receptor up to a micromolar concentration of Al3+ ions is reported in 50 mM HEPES buffer [pH 7.4; H2O: MeOH (9:1 v/v)]. The receptor was also utilized to detect Al3+ ions in living cells. [ABSTRACT FROM AUTHOR]

Two novel fluorescent probes, namely, 3-(2,4-dinitrophenoxy)-2-(4-(diphenylamino)phenyl)-4 H -chromen-4-one (P1) and 3-(2,4-dinitrophenoxy)-2-(pyren-1-yl)-4 H -chromen-4-one (P2), were designed and synthesized here. The probes (P1 and P2) were found to be highly selective and sensitive toward hydrogen sulfide (H 2 S) in the presence of a wide range of anions. The new probes (P1 and P2) were fully characterized by analytical, NMR spectroscopy ( 1 H and 13 C), and ESI mass spectrometry. The sensing capability of chemodosimeters (P1 and P2) toward H 2 S was confirmed by fluorescence studies. The 'turn-on' fluorescence was used to calculate the detection limit of probes (LOD), which were found to be 2.4 and 1.2 μM for P1 and P2, respectively. Moreover, the probes were tested for their cytotoxicity against HeLa cells using the MTT assay and found to be non-cytotoxic in nature; hence, the probes P1 and P2 were successfully utilized to visualize H 2 S in the living cells.