A novel fluorometric chemical sensor (PY-2TH) based on 2-thiohydantoin (2TH) in conjugation with pyrene (PY) was designed by facile one-pot Knoevenagel condensation reaction and explored for the ...sensitive and selective detection of Hg2+ ion in solution and solid state methods. Different analytical techniques like NMR and LC-MS concomitantly confirmed the structure of PY-2TH. Absorption and emission studies demonstrate positive solvatochromic effects indicating intramolecular charge transfer in polar solvents. PY-2TH exhibits unprecedented selectivity for detecting Hg2+ ions in tetrahydrofuran (THF) through turn-OFF fluorescence with 90% decrease in the emission intensity with a limit of detection (LOD) of ∼4.4 ppb. The mechanistic investigation through NMR and optical studies confirm the formation of a 2:1 complex between PY-2TH and Hg2+. Thin films of PY-2TH exhibits the J-aggregate formation in the solid state leading to a shift in the emission towards the near-infrared region. Further, we have demonstrated the applicability of PY-2TH for detection of Hg2+ ions and fluorescence imaging in live Zebrafish larvae and the toxicological effects are explored. Cytotoxic evaluation on Zebrafish larval cells revealed that PY-2TH is found to be non-toxic. Detailed analysis demonstrate the potential of PY-2TH for ultra-sensitive Hg2+ ion detection and removal in aqueous environments, highlighting its applicability for identification of metal contamination in live organisms and environmental toxicity.
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•Novel fluorescent PY-2TH designed using 2-thiohydantoin and pyrene through one-pot Knoevenagel condensation reaction.•Solvatochromic effects observed in absorption and emission studies concur intramolecular charge transfer in polar solvents.•PY-2TH demonstrates remarkable selectivity for detection of Hg2+ ions, exhibiting turn-OFF behaviour with LOD of 22 nM.•Assess the metal contamination in live organisms and environmental toxicity.
Corrosion is a harmful processes which by definition is a chemical or electrochemical reaction between a substance (usually a metal) and the environment which leads to a change in the properties of ...the substance and has destructive effects. In this study, new composites consisting of Al/WS2/ZnTerp-2TH with 5 and 10 wt.% ZnTerp-2TH were prepared and the results were fully compared. Al/WS2 played the role of matrix and ZnTerp-2TH played the role of reinforcement. In other words, as a novelty to prevent the corrosion of Al/WS2, ZnTerp-2TH is designed and synthesized and showed good results when the corrosion ratio was reduced by the existence of ZnTerp-2TH. Furthermore, the NMR and mass analysis of ZnTerp-2TH were carried out, and the thermal properties, X-ray diffraction, Fourier-transform infrared (FTIR) spectroscopy, morphology, energy-dispersive X-ray spectroscopy (EDX) analysis and corrosion behavior of the composites were also discussed in detail. The crystal size values of composites were calculated by the modified Scherrer method 34, 26 and 27 nm for Al/WS2, Al/WS2/5 wt.% ZnTerp-2TH and Al/WS2/10 wt.% ZnTerp-2TH, respectively. The microstructural examination of the specimens showed that the reinforcing phase (ZnTerp-2TH) has a favorable distribution on the surface of Al/WS2 when it covers the cracks and holes. In addition, the corrosion investigation results showed that the addition of ZnTerp-2TH to Al/WS2 can improve the corrosion resistance when the Ecorr and Icorr values of Al/WS2/10 wt.% ZnTerp-2TH were recorded in tandem −724 mV/decade and 5 uA cm−2.
A novel fluorescent chemosensor (
TPA-2TH
) containing triphenylamine (TPA) appended in conjugation with 2-thiohydantoin (2TH) is developed and confirmed by various analytical techniques like FT-IR ...spectroscopy, NMR spectroscopy, HR-MS and single crystal X-ray diffraction (SC-XRD). The crystal structure analysis revealed a propeller-shaped TPA unit and a co-facial herringbone packing arrangement stabilized by N-H S, N-H O and C-H O in the crystal lattice.
TPA-2TH
exhibited a strong absorption band at ∼431 nm and emitted a yellow-green fluorescence at
λ
max
= 522 nm in THF, attributed to an efficient charge-separated state resulting from ICT between TPA and 2TH. A solvatochromic effect was observed with a red shift in the emission wavelength as the polarity of the solvent increased.
TPA-2TH
showed unprecedented selectivity with
turn-off
fluorescence upon complexation with diamagnetic Hg
2+
ions, attributed to an increase in the spin-orbit coupling and a weakened ICT effect caused by Hg
2+
binding. The addition of Hg
2+
to
TPA-2TH
resulted in the formation of a 2 : 1 complex (
TPA-2TH
-Hg
2+
), confirmed by the coordination of a sulphur atom of
TPA-2TH
with Hg
2+
ions, as evidenced by
1
H NMR spectroscopy and Job's plot analysis. A linear relationship between the fluorescence intensity of
TPA-2TH
and the concentration of Hg
2+
ions is observed with a LOD of 3.3 pM. Furthermore, the toxicological effect of
TPA-2TH
is explored in zebrafish larvae and embryos to provide a sensitive bio-indicator for metal ion contamination and fluorescence imaging. This comprehensive approach combining fluorescence quenching and behavioural toxicity assessment offers a practical method for evaluating metal ion contamination and its potential toxic effects on aquatic organisms with acute behavioural toxicity end points using adult zebrafish.
A novel triphenylamine based push-pull fluorophore (
TPA-2TH
) bearing a 2-thiohydantoin unit for detection of toxic Hg
2+
ion and its live cell imaging in Zebrafish.
Tuning the π-conjugation and varying the functional units can improve the response behavior with superior sensitivity and selectivity. Herein, we report on five novel donor–acceptor (D–A) molecular ...ensembles developed through C5 substitution on 2-thiohydantoin (2TH) with π-conjugation having different electron-donating groups. The structure–property relationships were investigated by single-crystal X-ray diffraction (SC-XRD) analysis, photophysical, electrochemical, and computational studies. The structural influence of 2TH derivatives on surface interactions with volatile organic compounds (VOCs) were analyzed by binding affinities, kinetics, and other intrinsic parameters (work function, surface photovoltages (SPVs), and response and recovery times). N,N-diMeAPh-2TH exhibits mechanochromic and vapochromic behavior, shows red-shifted emission at ∼554 nm upon exposure to nonanal vapors with a visual color change from orange-red to brown, and shows vivid color variations with different VOCs. N,N-diMeAPh-2TH shows reversible vapochromic behavior as well. Ph-2TH, 4-OMePh-2TH, and 2,4-diOMePh-2TH exhibit n-type behavior with the greater SPV response achieved for Ph-2TH (90%), but good recovery (58%) in SPV in 439 s is observed in the case of 2,4-diOMePh-2TH. In contrast, 3,4-diOMePh-2TH and N,N-diMeAPh-2TH exhibit p-type behavior toward nonanal vapors with a high SPV response obtained for N,N-diMeAPh-2TH (94%) within 293 s as well as recovery (87%) in surface PVT in 692 s. The results demonstrate that electron-donating substituents −N(CH3)2 can improve sensing performance by increasing electron density, whereas steric hindrance on the phenyl unit can modulate sensing performance.
Corrosion is a harmful processes which by definition is a chemical or electrochemical reaction between a substance (usually a metal) and the environment which leads to a change in the properties of ...the substance and has destructive effects. In this study, new composites consisting of Al/WSsub.2/ZnTerp-2TH with 5 and 10 wt.% ZnTerp-2TH were prepared and the results were fully compared. Al/WSsub.2 played the role of matrix and ZnTerp-2TH played the role of reinforcement. In other words, as a novelty to prevent the corrosion of Al/WSsub.2, ZnTerp-2TH is designed and synthesized and showed good results when the corrosion ratio was reduced by the existence of ZnTerp-2TH. Furthermore, the NMR and mass analysis of ZnTerp-2TH were carried out, and the thermal properties, X-ray diffraction, Fourier-transform infrared (FTIR) spectroscopy, morphology, energy-dispersive X-ray spectroscopy (EDX) analysis and corrosion behavior of the composites were also discussed in detail. The crystal size values of composites were calculated by the modified Scherrer method 34, 26 and 27 nm for Al/WSsub.2, Al/WSsub.2/5 wt.% ZnTerp-2TH and Al/WSsub.2/10 wt.% ZnTerp-2TH, respectively. The microstructural examination of the specimens showed that the reinforcing phase (ZnTerp-2TH) has a favorable distribution on the surface of Al/WSsub.2 when it covers the cracks and holes. In addition, the corrosion investigation results showed that the addition of ZnTerp-2TH to Al/WSsub.2 can improve the corrosion resistance when the Esub.corr and Isub.corr values of Al/WSsub.2/10 wt.% ZnTerp-2TH were recorded in tandem −724 mV/decade and 5 uA cmsup.−2.
A novel fluorometric chemical sensor (PY-2TH) based on 2-thiohydantoin (2TH) in conjugation with pyrene (PY) was designed by facile one-pot Knoevenagel condensation reaction and explored for the ...sensitive and selective detection of Hg
ion in solution and solid state methods. Different analytical techniques like NMR and LC-MS concomitantly confirmed the structure of PY-2TH. Absorption and emission studies demonstrate positive solvatochromic effects indicating intramolecular charge transfer in polar solvents. PY-2TH exhibits unprecedented selectivity for detecting Hg
ions in tetrahydrofuran (THF) through turn-OFF fluorescence with 90% decrease in the emission intensity with a limit of detection (LOD) of ∼4.4 ppb. The mechanistic investigation through NMR and optical studies confirm the formation of a 2:1 complex between PY-2TH and Hg
. Thin films of PY-2TH exhibits the J-aggregate formation in the solid state leading to a shift in the emission towards the near-infrared region. Further, we have demonstrated the applicability of PY-2TH for detection of Hg
ions and fluorescence imaging in live Zebrafish larvae and the toxicological effects are explored. Cytotoxic evaluation on Zebrafish larval cells revealed that PY-2TH is found to be non-toxic. Detailed analysis demonstrate the potential of PY-2TH for ultra-sensitive Hg
ion detection and removal in aqueous environments, highlighting its applicability for identification of metal contamination in live organisms and environmental toxicity.
A novel fluorescent chemosensor (TPA-2TH) containing triphenylamine (TPA) appended in conjugation with 2-thiohydantoin (2TH) is developed and confirmed by various analytical techniques like FT-IR ...spectroscopy, NMR spectroscopy, HR-MS and single crystal X-ray diffraction (SC-XRD). The crystal structure analysis revealed a propeller-shaped TPA unit and a co-facial herringbone packing arrangement stabilized by N–H⋯S, N–H⋯O and C–H⋯O in the crystal lattice. TPA-2TH exhibited a strong absorption band at ∼431 nm and emitted a yellow-green fluorescence at λ max = 522 nm in THF, attributed to an efficient charge-separated state resulting from ICT between TPA and 2TH. A solvatochromic effect was observed with a red shift in the emission wavelength as the polarity of the solvent increased. TPA-2TH showed unprecedented selectivity with turn-off fluorescence upon complexation with diamagnetic Hg 2+ ions, attributed to an increase in the spin–orbit coupling and a weakened ICT effect caused by Hg 2+ binding. The addition of Hg 2+ to TPA-2TH resulted in the formation of a 2 : 1 complex (TPA-2TH–Hg 2+ ), confirmed by the coordination of a sulphur atom of TPA-2TH with Hg 2+ ions, as evidenced by 1 H NMR spectroscopy and Job's plot analysis. A linear relationship between the fluorescence intensity of TPA-2TH and the concentration of Hg 2+ ions is observed with a LOD of 3.3 pM. Furthermore, the toxicological effect of TPA-2TH is explored in zebrafish larvae and embryos to provide a sensitive bio-indicator for metal ion contamination and fluorescence imaging. This comprehensive approach combining fluorescence quenching and behavioural toxicity assessment offers a practical method for evaluating metal ion contamination and its potential toxic effects on aquatic organisms with acute behavioural toxicity end points using adult zebrafish.
The design of portable devices by immobilization of sensory probes using donor–acceptor (D–A) architectures enables the visual detection and onsite analysis of volatile organic compounds (VOCs). In ...this work, we have reported on the synthesis of different D–A architectures of 2-thiohydantoin (2TH) derivatives by extending the conjugation with phenyl (Ph-2TH), naphthalene (Naptha-2TH), and anthracene (Anthra-2TH) moieties at the C5 position. Single-crystal X-ray analysis reveals that extending the conjugation leads to variation in the molecular arrangement in the crystal lattice. Ph-2TH and Naptha-2TH show ribbon-like self-assembled layered arrangements, whereas Anthra-2TH crystallized in herringbone packing in the crystal lattice. The C–S···H interactions were varied with interatomic distances of 2.67, 2.63, and 2.27 Å, respectively, for phenyl, naphthalene, and anthracene. The photophysical and excited-state gas-phase interactions using scanning kelvin probe studies reveal that 2TH ensembles alter their surface photovoltages toward recognition of different VOCs (like ethanol, acetone, toluene, triethylamine, nonanal, and chloroform) depending on their donor and acceptor nature. All three 2TH derivatives showed n-type behavior with high selectivity toward nonanal, and Anthra-2TH exhibited high response (91.02%) within 278 s as well as recovery (92.83%) in surface photovoltages in 647 s. Combined experimental and computational studies demonstrate that the aromatic moieties appended 2TH ensembles would be an efficient D–A ensemble for the detection of VOCs containing carbonyl and alcohol functionalities aiding strong intermolecular interactions.
The inorganic phosphors doped with different rare earth ions are of more significant to develop new class of lighting devices to fulfill the present technological desires owing to their compact size, ...high colour rendering index with high luminescence efficiency, eco-friendly behaviour. The present research work reports the synthesis, structural, morphological and optical analysis of Sr3Gd(PO4)3: Tb3+ phosphors for lighting applications. These phosphors were synthesized via modified citrate gel-combustion technique with varied concentrations of Tb3+ and they were crystallized into BCC phase. The morphological investigations reveal an agglomeration of particles distributed non-uniformly in the crystal lattice. Upon excited at near UV radiation, the phosphors emit intense green luminescence through 5D4 → 7FJ transitions. The colour perception studies were carried out by evaluating the chromaticity coordinates (x, y). The experimental investigations explore that the studied phosphors are more suitable for lighting applications.
