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Metal-organic framework based highly selective fluorescence turn-on probe for hydrogen sulphide.

Nagarkar SS, Saha T, Desai AV, Talukdar P, Ghosh SK - Sci Rep (2014)

Bottom Line: Discerning the pathways of H2S production and its mode of action is still a challenge owing to its volatile and reactive nature.The MOF shows highly selective and fast response towards H2S even in presence of other relevant biomolecules.Low cytotoxicity and H2S detection in live cells, demonstrate the potential of MOF towards monitoring H2S chemistry in biological system.

View Article: PubMed Central - PubMed

Affiliation: Indian Institute of Science Education &Research (IISER), Pune Dr. Homi Bhabha Road, Pashan, Pune-411008 (India).

ABSTRACT
Hydrogen sulphide (H2S) is known to play a vital role in human physiology and pathology which stimulated interest in understanding complex behaviour of H2S. Discerning the pathways of H2S production and its mode of action is still a challenge owing to its volatile and reactive nature. Herein we report azide functionalized metal-organic framework (MOF) as a selective turn-on fluorescent probe for H2S detection. The MOF shows highly selective and fast response towards H2S even in presence of other relevant biomolecules. Low cytotoxicity and H2S detection in live cells, demonstrate the potential of MOF towards monitoring H2S chemistry in biological system. To the best of our knowledge this is the first example of MOF that exhibit fast and highly selective fluorescence turn-on response towards H2S under physiological conditions.

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Synthesis and characterization of MOF 1-NH2 and 1-N3.(a) PXRD patterns of MOFs 1-NH2 Simulated, 1-NH2, 1-N3 demonstrating the stability of MOF before and after chemical modification. (b) FT-IR spectra of MOFs 1-NH2 and 1-N3 clearly showing the appearance of new peak corresponding to –N3 confirming chemical modification of –NH2 to –N3 functionality in MOF. (c) 1H-NMR of acid digested MOFs 1-NH2, 1-N3 and 1-N3 upon Na2S treatment.
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f2: Synthesis and characterization of MOF 1-NH2 and 1-N3.(a) PXRD patterns of MOFs 1-NH2 Simulated, 1-NH2, 1-N3 demonstrating the stability of MOF before and after chemical modification. (b) FT-IR spectra of MOFs 1-NH2 and 1-N3 clearly showing the appearance of new peak corresponding to –N3 confirming chemical modification of –NH2 to –N3 functionality in MOF. (c) 1H-NMR of acid digested MOFs 1-NH2, 1-N3 and 1-N3 upon Na2S treatment.

Mentions: Probe 1-N3 was synthesized using 1-NH2 as precursor, as the use of azide functionalized ligand did not yield desired product. 1-NH2 was synthesized solvothermally using 2-aminoterephtalic acid and ZrCl4 with DMF as solvent51. The phase purity of bulk compound was confirmed by matching powder X-ray diffraction (PXRD) patterns of simulated and as-synthesized bulk compound (Fig. 2a). The thermogravimetric analysis revealed that MOF lose entrapped solvent molecules on heating and remains stable up to 350°C (Supplementary Fig. S1). The occluded guest molecules in 1-NH2 were exchanged with low boiling MeOH over 5 days and the exchanged MeOH molecules were then removed by thermal treatment under reduced pressure to get guest free porous 1-NH2. The activation of 1-NH2 was confirmed by N2 adsorption isotherm at 77 K (Supplementary Fig. S2). Further the chemical modification of free –NH2 to –N3 was achieved by diazotization of -NH2 followed by NaN3 treatment (for details please see experimental section). 1-N3 was then exchanged with H2O for 2 days and then activated under reduced pressure. The structural integrity of MOF upon post-synthetic modification was confirmed by PXRD patterns. The overlapping PXRD patterns of 1-NH2 and 1-N3 confirmed the structural integrity of 1-N3 (Fig. 2a). The FT-IR spectrum –N3 showed appearance of new distinct peak at 2127 cm−1 corresponding to azide group which is absent in 1-NH2 confirmed the transformation of –NH2 to –N3 (Fig. 2b). The chemical transformation was further confirmed using 1H-NMR. The 1-NH2 and 1-N3 were digested with DMSO-d6 and HF to get clear solution which was then subjected to NMR analysis. 1H-NMR of 1-NH2 showed peak corresponding to ammonium protons, this peak was absent in 1-N3 which also confirmed the successful transformation of –NH2 to –N3 (Fig. 2c).


Metal-organic framework based highly selective fluorescence turn-on probe for hydrogen sulphide.

Nagarkar SS, Saha T, Desai AV, Talukdar P, Ghosh SK - Sci Rep (2014)

Synthesis and characterization of MOF 1-NH2 and 1-N3.(a) PXRD patterns of MOFs 1-NH2 Simulated, 1-NH2, 1-N3 demonstrating the stability of MOF before and after chemical modification. (b) FT-IR spectra of MOFs 1-NH2 and 1-N3 clearly showing the appearance of new peak corresponding to –N3 confirming chemical modification of –NH2 to –N3 functionality in MOF. (c) 1H-NMR of acid digested MOFs 1-NH2, 1-N3 and 1-N3 upon Na2S treatment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231339&req=5

f2: Synthesis and characterization of MOF 1-NH2 and 1-N3.(a) PXRD patterns of MOFs 1-NH2 Simulated, 1-NH2, 1-N3 demonstrating the stability of MOF before and after chemical modification. (b) FT-IR spectra of MOFs 1-NH2 and 1-N3 clearly showing the appearance of new peak corresponding to –N3 confirming chemical modification of –NH2 to –N3 functionality in MOF. (c) 1H-NMR of acid digested MOFs 1-NH2, 1-N3 and 1-N3 upon Na2S treatment.
Mentions: Probe 1-N3 was synthesized using 1-NH2 as precursor, as the use of azide functionalized ligand did not yield desired product. 1-NH2 was synthesized solvothermally using 2-aminoterephtalic acid and ZrCl4 with DMF as solvent51. The phase purity of bulk compound was confirmed by matching powder X-ray diffraction (PXRD) patterns of simulated and as-synthesized bulk compound (Fig. 2a). The thermogravimetric analysis revealed that MOF lose entrapped solvent molecules on heating and remains stable up to 350°C (Supplementary Fig. S1). The occluded guest molecules in 1-NH2 were exchanged with low boiling MeOH over 5 days and the exchanged MeOH molecules were then removed by thermal treatment under reduced pressure to get guest free porous 1-NH2. The activation of 1-NH2 was confirmed by N2 adsorption isotherm at 77 K (Supplementary Fig. S2). Further the chemical modification of free –NH2 to –N3 was achieved by diazotization of -NH2 followed by NaN3 treatment (for details please see experimental section). 1-N3 was then exchanged with H2O for 2 days and then activated under reduced pressure. The structural integrity of MOF upon post-synthetic modification was confirmed by PXRD patterns. The overlapping PXRD patterns of 1-NH2 and 1-N3 confirmed the structural integrity of 1-N3 (Fig. 2a). The FT-IR spectrum –N3 showed appearance of new distinct peak at 2127 cm−1 corresponding to azide group which is absent in 1-NH2 confirmed the transformation of –NH2 to –N3 (Fig. 2b). The chemical transformation was further confirmed using 1H-NMR. The 1-NH2 and 1-N3 were digested with DMSO-d6 and HF to get clear solution which was then subjected to NMR analysis. 1H-NMR of 1-NH2 showed peak corresponding to ammonium protons, this peak was absent in 1-N3 which also confirmed the successful transformation of –NH2 to –N3 (Fig. 2c).

Bottom Line: Discerning the pathways of H2S production and its mode of action is still a challenge owing to its volatile and reactive nature.The MOF shows highly selective and fast response towards H2S even in presence of other relevant biomolecules.Low cytotoxicity and H2S detection in live cells, demonstrate the potential of MOF towards monitoring H2S chemistry in biological system.

View Article: PubMed Central - PubMed

Affiliation: Indian Institute of Science Education &Research (IISER), Pune Dr. Homi Bhabha Road, Pashan, Pune-411008 (India).

ABSTRACT
Hydrogen sulphide (H2S) is known to play a vital role in human physiology and pathology which stimulated interest in understanding complex behaviour of H2S. Discerning the pathways of H2S production and its mode of action is still a challenge owing to its volatile and reactive nature. Herein we report azide functionalized metal-organic framework (MOF) as a selective turn-on fluorescent probe for H2S detection. The MOF shows highly selective and fast response towards H2S even in presence of other relevant biomolecules. Low cytotoxicity and H2S detection in live cells, demonstrate the potential of MOF towards monitoring H2S chemistry in biological system. To the best of our knowledge this is the first example of MOF that exhibit fast and highly selective fluorescence turn-on response towards H2S under physiological conditions.

Show MeSH
Related in: MedlinePlus