Journal of Fluorescence最新文献

Acridine-based hybrid fluorescent dyes represent a category of dyes that integrate the acridine chromophore with other functional groups or materials to enhance their fluorescence properties. These dyes have garnered substantial attention across various domains, encompassing bioimaging, sensing, and optoelectronics. In recent years, researchers have directed their efforts toward fabricating acridine-based hybrid fluorescent dyes with improved water solubility, biocompatibility, and targeting capabilities. These advancements have facilitated their utilization in biological imaging applications, such as monitoring cellular processes, investigating protein-protein interactions, and detecting specific biomolecules. This review delineates the recent progress in synthesizing acridine-based hybrid fluorescent dyes and their applications in optical properties over the past decade. This review is anticipated to catalyze the development of innovative fluorescent materials featuring heightened properties and functionalities.

We have synthesized Murraya Koenigii leaves powder-derived carbon nanodots (CNDs) by hydrothermal method. A tribute to our commitment to environmental sustainability is the unique composition of our CNDs, which are made entirely of natural carbon sources and a green solvent, water. Our further efforts to improve performance led us to start making nitrogen-doped CNDs. By using urea as a non-toxic source of nitrogen, we observed a substantial increase in fluorescence intensity, extending the usefulness and potential of these nanomaterials. We investigated the optical properties using UV-Vis and fluorescence spectroscopy. The other parameters, like structural and size-shape morphology, were analyzed using FTIR, XRD, and HR-TEM, respectively. The fluorescence spectroscopy demonstrated their capability to exhibit wavelength-dependent photoluminescence (PL), highlighting the potential of these CNDs for cell bioimaging applications. The fluorescence properties affirm their suitability for biomedical applications, as they do not involve any inherent risk to cells.

In this study, a novel fluorescent probe based on CuInS₂ quantum dots modified with alanine (Ala-CuInS₂ QDs) was developed for the detection of lead ions and cysteine (Pb²⁺ and Cys). Ala-CuInS₂ QDs were synthesized through a one-step hydrothermal method exhibiting uniform size, good stability and water solubility. The QDs were then utilized as an "on-off-on" fluorescence sensor to detect Pb²⁺ and Cys in the ranges of 0-20 µM and 0-55 µM respectively, with detection limits of 0.29 µM and 0.66 µM. The mechanism of fluorescence quenching and recovery processes was also explored. Furthermore, Ala-CuInS₂ QDs have been successfully applied to detect Pb²⁺ in tap and river water and detect cysteine in serum.

In this work, carbon quantum dots (CQDs) were prepared using a one-step hydrothermal green synthesis method from a low-cost and eco-friendly renewable biomass, specifically the Ficus benghalensis aerial roots (FB-AR). For the past two decades, CQDs have been noted for their tunable emission spectrum, quantum yield, biocompatibility, photostability, and unique optoelectronic properties such as photoluminescence (PL), and fluorescence. The synthesized Ficus benghalensis carbon quantum dots (FB-CQDs) were characterized for their physical, structural, and chemical properties using XRD, Raman, HRTEM, XPS, FTIR, TG-DTG, UV-visible, and photoluminance analysis. XPS analysis confirmed the presence of phytoconstituent functionalities and the composition of components. The FB-CQDs, which exhibit long-range emissions, have potential applications in various biological and therapeutic fields. Their bioimaging capability is tested in Escherichia coli bacteria. However, despite their promising characteristics, the FB-CQDs showed no antibacterial inhibition against Escherichia coli and Staphylococcus aureus, likely due to its carbonization temperature.

A novel imidazo[1,2-a]pyridine derivative probe (R) was designed, synthesized, and characterized via various characterization techniques, such as ESI-MS, ¹H NMR, ¹³C NMR, and Dept-135 NMR. The data obtained from single-crystal XRD reveal that probe R has a coplanar configuration and is part of the monoclinic crystal system, designated the P2(1)/n space group. The fluorescence of (R) is further enhanced by silver (I) ions. On the other hand, Hg²⁺ significantly quenches the fluorescence of probe R. The presence of other common metal ions does not influence the fluorescence of probe R in the CH₃CN: H₂O (1:1) mixture, as they neither increase nor quench it. From the fluorescence enhancement data, the low detection limit (LOD) for Ag + ions was determined to be 1.24 × 10^- 8 M, whereas the quenching caused by Hg²⁺ resulted in an LOD of 5.69 × 10^- 9 M. The complex of probe R with Ag⁺/Hg²⁺ exhibited a 1:1 stoichiometry, as confirmed by mass spectrometry and a Job plot. Single-crystal XRD analysis of R and its complex with Hg²⁺ revealed a loss of coplanarity, which confirmed their nonfluorescent behavior. We present a promising application of probe R in visualizing living Rhizoctonia oryzae cells exposed to silver (I) and mercury (II) ions.

Homogeneous light-initiated chemiluminescence technology (LICA) is widely used in clinical diagnostics due to the advantages of high sensitivity, minimal reagent usage, and no need for washing. Luminescent microspheres receive singlet oxygen emitted by photosensitive microspheres to generate optical signals. Therefore,¹O₂-initiated luminescent nanospheres are crucial, but there are few reports on the preparation of ¹O₂-initiated luminescent nanospheres. Herein, monodisperse luminescent Eu/C-28@PS (Eps) nanospheres were prepared and optimized using chelate Eu (TTA)₃phen and 4-(2-phenyl-5,6-dihydro1,4-oxathiin-3-yl)-N, N-ditetradecylbenzenamine (C-28) as probe dye via THF/water swelling-shrinking procedure. Various swelling parameters were studied to obtain the swelling conditions that produce the minimum particle size and narrow size distribution, which shows good results in uniform particle size distribution (~ 250 nm, a PDI of 0.03), surface carboxylate content (1.18 mmol/g), and BSA loading capability (129.8 mg/g) in the case of 20 mg total probe dosage and 2 h of incubation at 40 °C using 14% THF/water mixture as a co-solvent system. The composition of the entrapped probe has a gain effect on the ¹O₂-initiated fluorescent signal and the optimal ratio of Eu (TTA)₃phen: C-28 (1:1) was obtained on a commercial analyzer using IgG and anti-human IgG as models in PBS buffer. These results indicate that monodisperse luminescent Eps nanospheres are suitable as light-initiated chemiluminescence sensors and have great application potential in early detection, screening tests, and prognostic evaluation of patients.

The development of fluorescent probes for H₂S detection especially in living cells is of great significance due to its fundamental role as signal molecule. A promising scaffold for the development of such probes is polydimethylsiloxanes (PDMS), which is cost-effectiveness, non-toxicity, flexibility, and biocompatibility and easy to post-functionalize. Surprisingly, fluorescent probes for H₂S detection based on PDMS have not been investigated. Moreover, 4-nitro - 2,1,3-benzoxadiazole (NBD) derivates provides high fluorescence quantum yield, a large molar absorption coefficient, and sensitivity to environmental changes. Through reasonable design and adjustment of substituents on the NBD group, precise control of its fluorescence properties can be achieved. Herein, a novel H₂S fluorescent probe, P-NBD, was designed and synthesized by a one-step aromatic ring nucleophilic substitution of Cl-NBD with a PDMS derivative. Due to the occurrence of the cleavage reaction strategy and the intramolecular charge transfer process, P-NBD can detect H₂S via a colorimetric method. The limit of detection is down to 93 nM. P-NBD demonstrated considerable detection capability comparable to other reported types of H₂S probes. Moreover, the probe can also be utilized for H₂S imaging in HeLa cells. This work provides new insights into the design and synthesis of novel H₂S probes while also offering experimental evidence for the application of PDMS in cellular imaging.

Phosphites are being recognized as the new emerging candidates for luminescence in the modern era. In the proposed research article, Ce³⁺/Eu²⁺ co-activated NaBa(PO₃)₃ phosphite phosphors synthesized utilizing sol-gel technique. Through the use of XRD and Rietveld refinement, the phase identity and crystal structure of produced phosphor are examined. SEM is employed to analyze the morphology and elemental composition of the prepared sample. The sample shows blue emission enhancement in the phosphor on energy transfer with the Ce³⁺ ion by 6 times. This highly instance blue emitting phosphor has color purity of 98.49%. These all results confirm that the prepared phosphor is potential candidate for WLEDs, display applications and blue emitting phosphor for plant cultivation applications.

Spectroanalytical techniques are extensively employed in contemporary research to characterize compounds and assess their biological activity. The β-lactam ring containing twenty novel spiro quinoxaline-pyridine heterocyclic compounds (A - T) were synthesized and characterized using ¹H NMR, ¹³C NMR, FT-IR, and mass spectrometry. The compounds must interact with DNA to adequately assess their potential anticancer action. Thus, their binding affinities with calf-thymus (CT) DNA and bovine serum albumin (BSA) were evaluated using a UV-visible spectrophotometer. The K_b value of compound-DNA and compound-BSA was found in the order of 0.51-2.53 M^- 1 and 0.11-2.03 M^- 1, respectively. Furthermore, a fluorescence quenching study was also carried out using a fluorescence spectrometer to explore DNA/BSA binding, and a partial intercalation type of binding was suggested. MTT assay was performed to evaluate the anticancer activity of the compounds. A docking study of all the compounds was performed with DNA (1 BNA), BSA (4F5S), and topoisomerase II (3QX3) using autodock vina software. SwissADME and admetSAR, two online platforms, were used to assess the pharmacokinetic profile and determine the drug-likeness of the synthesized compounds.

Although Cr(III) ions are essential for the human body, excessive amounts can lead to skin inflammation, allergic reactions, and genotoxicity. A highly sensitive fluorescence probe was developed using mercaptopropionic acid (MPA) capped CdZnTe quantum dots (QDs) synthesized via an aqueous solution heating method for precise detection of Cr(III) ions. The synthesized MPA-CdZnTe QDs had a size of 2.38 ± 0.13 nm and exhibited a zinc-blende structure, with MPA molecules effectively capping the surface through Cd-S bonds. Investigation into the effects of reflux times and solution pH on the absorption and fluorescence spectra of MPA-CdZnTe QDs revealed the occurrence of Ostwald ripening during prolonged reflux processes. The quantum yield (QY) of the synthesized CdZnTe QDs could reach 89%, and the QY was higher under acidic conditions than alkaline. Leveraging the quenching effect of Cr(III) ions on MPA-CdZnTe QDs, a robust method for the quantitative detection of trace amounts of Cr(III) ions was established. Linear quenching behavior was observed within the concentration range of 3.33 × 10^- 6 to 5.00 × 10^- 4 mol L^- 1 for Cr(III) ions, with the fluorescence quenching rate described by a linear regression equation: 1-F/F₀ = 0.218 + 829.5268C_Cr(III). The limit of detection was determined to be 2.63 × 10^- 6 mol L^- 1. The mechanism of the fluorescence behavior of MPA capped CdZnTe QDs towards Cr(III) ions was photo-induced electron transfer.