Journal of Fluorescence最新文献

Extensive surgical resection improves survival in cancer patients. Fluorescence-guided imaging techniques have significantly enhanced the precision of cancer resections. Triple-negative breast cancer (TNBC) lacks expression of the estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2), and no other targetable molecules have been identified. In this study, we verified that the L-type amino acid transporter 1 (LAT1, also known as SLC7A5) is overexpressed in triple-negative breast cancer (TNBC) cells and we constructed a novel near-infrared fluorescent dye Cys-PEG₅-IR target to SLC7A5. We then report the SLC7A5 receptor specificity of Cys-PEG₅-IR as a contrast agent for TNBC imaging in vitro and in vivo. The conjugation elevated cell fluorescence on SLC7A5-overexpressing TNBC cells and produced minimal cell fluorescence when treated with SLC7A5 knockdown. Tumor uptake of Cys-PEG₅-IR was significantly higher than the unlabeled IR in the subcutaneous MDA-MB-231 TNBC xenograft. This work highlights the prospect of using methionine (Met) transport pathway as an alternative strategy for targeting cancer cells, especially TNBC cells.

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 achieve visualized, dynamic quantitative monitoring of Microthrix parvicella surface hydrophobicity during activated sludge filamentous bulking and to overcome the limitations of traditional methods in accurately characterizing filamentous bacteria hydrophobicity, seven fluorescent probes with distinct polarities were designed and synthesized based on the specific binding mechanism between lipid substrates and lipase. Results showed probe dipole moment and binding energy are key factors affecting staining efficiency. Probes with small dipole moments (< 10 Debye) and high binding energies (<-9.0 kcal/mol) stably bind to nonpolar regions of the cell membrane and lipase, maintaining staining ability but exhibiting low sensitivity to hydrophobicity changes. Probes with large dipole moments (> 20 Debye) and low binding energies (>-9.0 kcal/mol) were sensitive but lost staining ability rapidly as hydrophobicity decreased. Moderate-parameter probes exhibit a balance between stability and sensitivity, with fluorescence intensity consistent with M. parvicella growth cycle and Sludge Volume Index (SVI), thereby accurately reflecting hydrophobicity fluctuations during bulking.

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.

Levofloxacin (LEV) and ciprofloxacin (CIP) are widely common antibiotics. However, their misuse can lead to bacterial resistance and pose significant risks to both environment and human health. To address this issue, we synthesized and characterized two novel fluorescent composite materials: Fe₃O₄/HAP/Eu and Fe₃O₄/HAP/Tb. Fe₃O₄/HAP/Eu was designed for detection of LEV, whereas Fe₃O₄/HAP/Tb was developed for detection of CIP. The results showed that Fe₃O₄/HAP/Eu exhibited optimal excitation and emission wavelengths of 394 nm and 624 nm, respectively, with the fluorescence lifetime of 0.77 µs and the fluorescence quantum yield of 6.61%. Fe₃O₄/HAP/Tb performed optimal excitation and emission wavelengths of 370 nm and 551 nm, respectively, with the fluorescence lifetime of 1.06 µs and the fluorescence quantum yield of 8.28%. In terms of application, the linear range for detection of LEV was 1-50 µM, with detection limit of 0.67 µM. For CIP, linear range was 0.1-60 µM, and the detection limit was 0.086 µM. The two types of fluorescent composite provided reliable approach for detecting trace amounts of LEV and CIP in food. It demonstrated significant potential for practical applications in the fields of environment, food and medicine.