Journal of Fluorescence最新文献

The present work deals with the preparation and characterization of novel g-C₃N₄/Fe₂WO₆ (GCNFW) nanocomposite for the effective detection and removal of Fe(III). where thermal polymerization (g-C₃N₄), ball milling - solid state reaction (Fe₂WO₆) and ultrasonication (GCNFW nanocomposite) methods were adopted for the preparation. The structural and morphological studies of GCNFW nanocomposite ensure the presence of single-phase orthorhombic Fe₂WO₆ decorated g-C₃N₄ and the same was free from impurities. The selectivity of GCNFW was tested by considering 15 metal ions namely Hg(II), Ni(II), Cd(II), Co(II), Sn(IV), Al(III), Cr(III), Pb(II), Zn(II), In(III), Fe(III), Cu(II), As(III), Sr(II) and Ba(II). Interestingly the prepared GCNFW nanocomposite could behave as fluorescent sensor and electrochemical sensor. As a fluorescent sensor, GCNFW has remarkable "Turn-off" fluorescence selectivity towards Fe(III) with LOD of 26.6 nM. The Differential Pulse Voltammetry (DPV) studies confirmed the electrochemical sensing behaviour of GCNFW towards Fe(III) with LOD of 1.23 µM. The prepared GCNFW has achieved 303.30 mg/g adsorption capacity and 87.48% removal efficiency within 15 min. A prototype water purifier made of GCNFW with Polyurethane foam (GCNFW-PU) could have the maximum adsorption capacity of 0.098 mg/g and removal efficiency of 99.36% towards Fe(III) in the real time drinking water samples collected from 7 different localities at Madurai District, Tamil Nadu. Hence the prepared GCNFW nanocomposite may serve as a promising fluorescent as well as electrochemical sensor material for the effective detection and removal of Fe(III) in the realm of heavy metals polluted drinking water remediation applications.

To explore new luminescent materials, two novel luminescent salts, [HAD]⁺BSA⁻∙methanol (1) and [HAD]⁺TSA⁻∙methanol (2), incorporating the 4-amino-1,2,4-triazole functional moiety (AD = 4,4'-(4-amino-4H-1,2,4-triazole-3,5-diyl)dianiline), were successfully synthesized through reactions with benzenesulfonic acid and p-toluenesulfonic acid, respectively. Comprehensive characterization via single-crystal X-ray diffraction, FT-IR, UV-Vis, and PXRD revealed distinct photophysical properties governed by their supramolecular architectures. Solid-state emission studies demonstrated blue-shifted maxima at 443 nm for salt 1 and 449 nm for salt 2 compared to the free AD ligand (457 nm), corresponding to shifts of 14 nm and 8 nm, respectively. This emission modulation directly correlates with π∙∙∙π stacking interactions, where shorter stacking distances in salt 1 (3.878 Å) versus salt 2 (4.406 Å) enhance intermolecular electronic coupling. Hirshfeld surface analysis confirmed stronger C∙∙∙H contacts in salt 1, consistent with its more pronounced stacking interactions and shorter emission wavelength. The lifetimes can be observed to 1.41, 0.96 and 0.90 ns, while the quantum yields of compounds can be found to be 0.20, 0.26 and 0.38 for AD, 1 and 2, respectively. The study establishes definitive structure-property relationships, demonstrating that strategic manipulation of weak intermolecular forces provides an effective pathway for engineering luminescent properties in triazole-based materials through crystal engineering.

Introducing the new Quinoline-based Schiff base (BB-SB), crafted through a single-step condensation reaction between 5-aminoquinoline and 5-bromo-2-thiophene carboxaldehyde and meticulously characterized using a range of spectroscopic techniques. This synthesized compound showcases exceptional aggregation-induced enhanced emission (AIEE) properties, boasting a staggering 38-fold boost in fluorescence intensity and a 24 nm redshift when tested in a 50:50 acetonitrile-water blend, compared to pure DMF. The impressive AIEE performance was further validated by dynamic light scattering (DLS) analysis. BB-SB displays its ability to selectively identify Fe²⁺ and Hg²⁺ ions amidst a sea of 16 heavy metals, employing spectrofluorometric techniques with remarkable sensitivity. The limits of detection (LOD) for Fe²⁺ and Hg²⁺ stand at 3.3 μM and 1.3 μM, respectively. Job's plot analysis revealed a 1:2 ligand-to-metal binding stoichiometry for both ions. The quenching mechanism for mercury was delved into through Stern-Volmer plots, and was found to follow static quenching mechanism. Moreover, the aldehyde intermediate generated during the synthesis of BB-SB displayed intriguing solvatochromic behaviour, featuring donor and acceptor moieties. This feature highlights its potential as a candidate for color-tunable, solution-processable optoelectronic devices. While the present work focuses on sensing performance, the preliminary findings suggest that future exploration of the optoelectronic applications of these systems, including OLEDs, may be promising.

In this work, we report the green synthesis of fluorescent carbon dots (MS-CDs) from Mammea suriga leaves via a simple and efficient probe for environmental detoxification. The synthesized MS-CDs were spectroscopically characterized by UV-Vis spectroscopy, fluorescence spectroscopy, FTIR, HR-TEM, X-ray diffraction, and ¹³C NMR spectroscopy. The particle sizes were found to be in the range of 2.2-4.6 nm. FTIR analysis confirmed the presence of -OH functional groups, and XRD studies confirmed the amorphous nature of the MS-CDs. The synthesized MS-CDs were used as a photocatalyst in the degradation of Eosin B, exhibiting 90% and 68% degradation activity at pH 6 and pH 9, respectively, within 240 min. Furthermore, the biological studies reflected that the MS-CDs are a promising scaffold owing to their excellent antioxidant and anti-inflammatory properties with IC₅₀ values as 42.92 ± 0.92 and 34.00 ± 0.98 µg/mL respectively. Additionally, MS-CDS exhibited significant antidiabetic potency with IC₅₀ value as 33.57 ± 0.73 and 25.78 ± 0.51 µg/mL for α-amylase and α-glucosidase inhibition, respectively. This study highlights MS-CDs as promising dual-function materials, combining efficient photocatalytic performance with potent biological activities.

Compared to monomeric counterparts, excimer probes exhibit significantly red-shifted spectra, broadened emission profiles, and enhanced Stokes shifts, exhibiting distinctive advantages in bioimaging applications. In this work, we developed an excimer-forming membrane-targeting fluorogenic probe (DIPP) through covalent conjugation between two triphenylimidazole moieties via a 1,5-bis(pyridin-1-yl)pentane linker. In various organic solvents, DIPP demonstrated exclusive excimer fluorescence, except in DMSO where monomer-excimer dual emission was observed, whereas its monomeric counterpart (MIPP) exhibits predominant monomer fluorescence, demonstrating that dimerization enhances excimer formation. Notably, DIPP displays negligible fluorescence in aqueous solution but exhibits significantly enhanced excimer emission intensity upon incorporation into SDS micelles. Leveraging the environmental sensitivity of excimer emission, DIPP was employed as a membrane-targeting fluorescent probe demonstrating multiple advantages: bright red emission (> 610 nm), a large Stokes shift (Δλ > 210 nm), low cytotoxicity, rapid cellular internalization (~ 5 min), and wash-free imaging capability.

Herein, multifunctional fluorescent N-doped carbon dots (N-CDs) are synthesized from O-phenylenediamine and 4-aminobenzoic acid. Hydrothermal synthesis and nitrogen doping make the N-CDs possess good physical and chemical properties with bright emission at 567 nm (QY = 32%) and present obvious excitation dependence. Among common metal ions, only Cr(VI) strongly and linearly decrease the yellow fluorescence of N-CDs in wide concentration ranges of 20.0-180 µM and 180-350 µM. Thus, N-CDs are constructed as efficient fluorescence probe for Cr(VI) with detection limit of 1.94 µM. The mechanism of quenching is indicated as the inner filter effect (IFE). The proposed sensor has been successfully applied in two kinds of water samples. In addition, the CDs are tried to apply for cell imaging. Above experiments prove that N-CDs based sensors are efficient strategies for sensitive Cr(VI) detection and cell imaging.