Search

Here, we describe a new dinitro-functionalized Zr(iv) MOF (MOF = metal–organic framework) having a UiO-66 (UiO = University of Oslo) framework topology called UiO-66-(NO2)2 (1). It shows fluorescence turn-on behavior towards H2S in simulated biological medium (HEPES buffer, pH = 7.4). By employing solvothermal conditions, 1 was successfully synthesized by reacting ZrCl4, H2BDC-(NO2)2 [H2BDC-(NO2)2 = 2,5-dinitro-1,4-benzenedicarboxylic acid] ligand and benzoic acid with a molar ratio of 1 : 1 : 10 in DMF (DMF = N,N-dimethylformamide) at 130 °C for 24 h. The material was characterized by infrared spectroscopy, X-ray powder diffraction (XRPD) and thermogravimetric (TG) analyses. The compound not only displays highly sensitive fluorometric sensing of H2S but also exhibits a visually detectable colorimetric change towards H2S in daylight. Moreover, the high selectivity of 1′ towards H2S is retained even when several other biologically intrusive species co-exist in the sensing medium. The limit of detection (LOD) of the compound is 14.14 μM which lies in the range of the H2S concentration found in biological systems. Fluorescence microscopy studies on J774A.1 cells revealed the efficacy of the probe for imaging H2S in living cells. Moreover, this material can detect H2S in human blood plasma (HBP) and monitor the sulfide concentration in real water samples. All these features clearly demonstrate that the material has huge potential for highly selective sensing of both extracellular and intracellular H2S. [ABSTRACT FROM AUTHOR]

An Al(iii) metal–organic framework (MOF) called Al-MIL-53-N3 (1) was synthesized under solvothermal reaction conditions using Al(NO3)3·9H2O and H2BDC-N3 (H2BDC-N3 = 2-azido-1,4-benzenedicarboxylic acid) ligand in a DMF/water (DMF = N,N-dimethylformamide) mixture. Phase purity was checked by performing X-ray powder diffraction, infrared spectroscopy and thermogravimetric analysis. Thermogravimetric analysis suggests that 1 is highly stable up to 300 °C under air atmosphere. The activated 1 (called 1′) showed a very fast fluorescence response to H2S (turn-on) and Fe(iii) ions (turn-off) in an aqueous medium with excellent sensitivity and selectivity even in the presence of other potentially intrusive analytes. In the presence of H2S, the conversion of the azide moiety to amine is responsible for the fluorescence turn-on properties. On the other hand, the partial replacement of framework Al(iii) ions by Fe(iii) can be assigned for the selective detection behavior to Fe(iii) ions. The detection limits (90.47 nM for H2S and 0.03 μM for Fe(iii) ions in water) of 1′ are lower than those of the formerly reported MOF type of fluorescent sensors. The 1′-loaded J774A.1 macrophage cells are healthy and respond to intracellular H2S to exhibit strong blue fluorescence, confirming its suitability to detect H2S inside the cells. In addition, 1′ can detect H2S in human blood plasma (HBP) and sulfide ions in real water samples. These features make 1′ a very promising candidate for the on-site sensing of Fe(iii) ions and the detection of intracellular and extracellular H2S. [ABSTRACT FROM AUTHOR]

A new, azide-functionalized Al(iii)-based metal–organic framework (MOF) denoted as CAU-10-N3 (1, CAU = Christian-Albrechts-University) and consisting of the 5-azido-isophthalic acid (H2IPA-N3) ligand was employed as a reaction-based fluorescent turn-on probe for the detection of H2S. The activated compound (1′) showed fast, selective and highly sensitive sensing properties for extracellular H2S in HEPES buffer (10 mM, pH = 7.4). The material retained its high selectivity even in the presence of possibly competing biological species. The limit of detection of 1′ for H2S is 2.65 μM, which is lower than the earlier reports on MOFs for H2S sensing. The material displayed a short response time (420 s) and a significant increase (20-fold and 26-fold after 1 and 7 min of addition of Na2S, respectively) in the fluorescence intensity towards H2S. Macrophage cells loaded with probe 1′ exhibited blue fluorescence with a response time of 15 min after Na2S addition, indicating the suitability of the probe for intracellular H2S detection. Moreover, CAU-10-N3 featured excellent detection performance (quick response and 32-fold increment in fluorescence intensity after 7 min of Na2S addition) in water. Hence, it can be utilized to regulate the H2S level in aqueous samples collected from the environment. [ABSTRACT FROM AUTHOR]

Here, we describe a new dinitro-functionalized Zr(iv) MOF (MOF = metal-organic framework) having a UiO-66 (UiO = University of Oslo) framework topology called UiO-66-(NO 2 ) 2 (1). It shows fluorescence turn-on behavior towards H 2 S in simulated biological medium (HEPES buffer, pH = 7.4). By employing solvothermal conditions, 1 was successfully synthesized by reacting ZrCl 4 , H 2 BDC-(NO 2 ) 2 [H 2 BDC-(NO 2 ) 2 = 2,5-dinitro-1,4-benzenedicarboxylic acid] ligand and benzoic acid with a molar ratio of 1 : 1 : 10 in DMF (DMF = N,N-dimethylformamide) at 130 °C for 24 h. The material was characterized by infrared spectroscopy, X-ray powder diffraction (XRPD) and thermogravimetric (TG) analyses. The compound not only displays highly sensitive fluorometric sensing of H 2 S but also exhibits a visually detectable colorimetric change towards H 2 S in daylight. Moreover, the high selectivity of 1' towards H 2 S is retained even when several other biologically intrusive species co-exist in the sensing medium. The limit of detection (LOD) of the compound is 14.14 μM which lies in the range of the H 2 S concentration found in biological systems. Fluorescence microscopy studies on J774A.1 cells revealed the efficacy of the probe for imaging H 2 S in living cells. Moreover, this material can detect H 2 S in human blood plasma (HBP) and monitor the sulfide concentration in real water samples. All these features clearly demonstrate that the material has huge potential for highly selective sensing of both extracellular and intracellular H 2 S.

An Al(iii) metal-organic framework (MOF) called Al-MIL-53-N 3 (1) was synthesized under solvothermal reaction conditions using Al(NO 3 ) 3 ·9H 2 O and H 2 BDC-N 3 (H 2 BDC-N 3 = 2-azido-1,4-benzenedicarboxylic acid) ligand in a DMF/water (DMF = N,N-dimethylformamide) mixture. Phase purity was checked by performing X-ray powder diffraction, infrared spectroscopy and thermogravimetric analysis. Thermogravimetric analysis suggests that 1 is highly stable up to 300 °C under air atmosphere. The activated 1 (called 1') showed a very fast fluorescence response to H 2 S (turn-on) and Fe(iii) ions (turn-off) in an aqueous medium with excellent sensitivity and selectivity even in the presence of other potentially intrusive analytes. In the presence of H 2 S, the conversion of the azide moiety to amine is responsible for the fluorescence turn-on properties. On the other hand, the partial replacement of framework Al(iii) ions by Fe(iii) can be assigned for the selective detection behavior to Fe(iii) ions. The detection limits (90.47 nM for H 2 S and 0.03 μM for Fe(iii) ions in water) of 1' are lower than those of the formerly reported MOF type of fluorescent sensors. The 1'-loaded J774A.1 macrophage cells are healthy and respond to intracellular H 2 S to exhibit strong blue fluorescence, confirming its suitability to detect H 2 S inside the cells. In addition, 1' can detect H 2 S in human blood plasma (HBP) and sulfide ions in real water samples. These features make 1' a very promising candidate for the on-site sensing of Fe(iii) ions and the detection of intracellular and extracellular H 2 S.

A new, azide-functionalized Al(iii)-based metal-organic framework (MOF) denoted as CAU-10-N 3 (1, CAU = Christian-Albrechts-University) and consisting of the 5-azido-isophthalic acid (H 2 IPA-N 3 ) ligand was employed as a reaction-based fluorescent turn-on probe for the detection of H 2 S. The activated compound (1') showed fast, selective and highly sensitive sensing properties for extracellular H 2 S in HEPES buffer (10 mM, pH = 7.4). The material retained its high selectivity even in the presence of possibly competing biological species. The limit of detection of 1' for H 2 S is 2.65 μM, which is lower than the earlier reports on MOFs for H 2 S sensing. The material displayed a short response time (420 s) and a significant increase (20-fold and 26-fold after 1 and 7 min of addition of Na 2 S, respectively) in the fluorescence intensity towards H 2 S. Macrophage cells loaded with probe 1' exhibited blue fluorescence with a response time of 15 min after Na 2 S addition, indicating the suitability of the probe for intracellular H 2 S detection. Moreover, CAU-10-N 3 featured excellent detection performance (quick response and 32-fold increment in fluorescence intensity after 7 min of Na 2 S addition) in water. Hence, it can be utilized to regulate the H 2 S level in aqueous samples collected from the environment.