Journal of Fluorescence最新文献

Laryngeal cancer, a common malignant respiratory tumor, is primarily treated through surgery. However, challenges such as recurrence, metastasis, and drug resistance persist. In recent years, multifunctional drug delivery systems (DDS) based on nanoparticles have shown great potential in improving drug loading and release. We developed a biocompatible core-shell nanoparticle system with a zinc-based metal-organic framework (MOF) as the core, named CP1. The shell, composed of polyethyleneimine (PEI), folic acid, and calcium carbonate, forms a composite called CaCO₃-PEI-FA. This system enhances biocompatibility and increases the efficacy of biomedical applications. Encapsulating CP1 within the CaCO₃-PEI-FA shell allows for the targeted delivery of the anticancer drug doxorubicin (DOX) to laryngeal cancer cells (Hep-2), resulting in the CaCO₃-PEI-FA@CP1@DOX system. The CaCO₃-PEI-FA composite exhibits strong fluorescence with a peak around 350 nm, confirming successful synthesis and demonstrating its potential as a bioimaging probe. Importantly, the nanoparticle system without DOX showed low toxicity to normal human skin fibroblasts (HSF). In vitro cytology experiments revealed a 38% inhibition rate of Hep-2 cells after 24 h, highlighting the nanocomposite's significant potential in inhibiting laryngeal cancer cell proliferation and inducing apoptosis, underscoring its promise in targeted laryngeal cancer therapy.

Nitrogen and sulfur co-doped carbon dots (N, S-CDs) were prepared for dual-channel ratiometric fluorescence determination of mercury ions (Hg²⁺). The dual-emission N, S-CDs were synthesized using a simple one-pot hydrothermal treatment. When excited with visible light, N,S-CDs exhibited two emission peaks at 390 and 500 nm. Notably, the presence of Hg²⁺ caused a considerable decrease in the fluorescence of N, S-CDs at 500 nm, mainly due to the static quenching effect. In comparison, the fluorescence at 390 nm was almost unchanged. With a limit of detection (LOD) of 0.21 µM for Hg²⁺, the N, S-CDs were successfully applied to the unlabeled ratiometric fluorescence determination of Hg²⁺ in actual water samples with good recoveries (94.5-107.8%). In conclusion, this developed ratiometric fluorescent sensor provides a reliable, environmentally friendly, rapid, and efficient platform for detecting Hg²⁺ in environmental applications.

Glyoxal (GL) is a physiological reactive α-oxoaldehyde metabolite, produced by lipid peroxidation and autoxidation of glucose. In this work, a specific mitochondria-targeting fluorescent probe Z-GL for glyoxal has been developed by an introducing isopropyl group on the recognition site to tune the selectivity toward glyoxal. The probe showed high selectivity and sensitivity for glyoxal in an aqueous system. Importantly, the probe was able to visualize exogenous and endogenous glyoxal in living cells. Furthermore, the probe was mitochondria-targetable, and could be used for monitoring the level of intracellular glyoxal.

The development of potential toxic metal ion probes is of great significance in the field of environmental detection. Herein, two squaramide ligands (2a, 2b) were constructed by combining the characteristics of squaric acid and imine groups. 2a and 2b can recognize Cu²⁺ and Cd²⁺, with LOD of 1.26 × 10^-8 M and 2.04 × 10^-8 M, respectively, and have the advantages of fast response and wide pH range. The binding ratio and binding mode of the probe and the target ion were determined by Job's plot, ESI-MS, and ¹H NMR.

This study presents a series of six vivid green Tb(III) complexes, denoted by the general formula [Tb(L)₃.secondary sensitizers], where L represents 1-cyclopropyl-7-(4-ethylpiperazin-1-yl)-6-fluoro-4-oxoquinoline-3-carboxylic acid and secondary sensitizers consist of heterocyclic N-donor aromatic systems. The synthesis of these complexes were achieved through a solvent-assisted grinding method, and their characterization involved various techniques such as CHN analysis, FTIR, NMR, UV, XRD, and NIR spectroscopy. These analyses confirmed the successful synthesis of complexes with coordination between the quinoline moiety and the metal ion. Photoluminescence studies were conducted in solid and solution phases, revealing excellent luminescence properties. The bright green color emitted by the complexes upon exposure to UV rays was attributed to the hypersensitive ⁵D₄ → ⁷F₅ transition. J-O analysis indicated an asymmetrical coordination environment around in the complexes. Additionally, various radiative properties (A_red, A_nred, η, β_exp, σ_s) and band gap values were determined, highlighting the potential applications of these complexes in diverse optoelectronic fields. Chromaticity evaluation demonstrated high color purity in both solid and solution phases. Furthermore, the CCT value identified the solid complexes as a cool light source. Overall, the analyses supported the exceptional luminosity of synthesized complexes, positioning them as promising luminescent materials for a wide range of devices.

Construction of efficient chemosensors for highly specific and sensitive detection of mercury ions remains a great challenge. In this work a highly selective and sensitive probe CY was designed and synthesized by using coumarin fluorophore as the matrix and thioacetal moiety as the reactive recognition site for Hg²⁺. By virtue of the thiophilicity of Hg²⁺, probe CL could be hydrolyzed to deprotect and the thioacetal was transformed to the acyl group after the addition of Hg²⁺, the blue-green fluorescence was quenched and meanwhile the solution changed from light green to yellow. The detection limit of probe CY for Hg²⁺ was as low as 6.8 nM, and it could completely react with Hg²⁺ within 3 min. Moreover, probe CY exhibited good resistance against interference from competitive metal ions and biothiols, high stability in pH 1-11 and applicability for fluorogenic and chromogenic dual-modal detection of Hg²⁺ in real water samples over a broad range of pH 5-10.

Polycystic ovary syndrome (PCOS) is a multifactorial disease characterized by oxidative stress and follicular dysfunction, leading to menstrual irregularities, hyperandrogenism, and infertility. Traditional drug delivery methods often result in drug loss and side effects on normal tissues. To address these issues, we synthesized two novel Co(II)-containing coordination polymers (CPs), {[Co(L)(H₂O)₂]·2H₂O}n (1) and {[Co(L)(H₂O)₂]·1.5H₂O}n (2), through the reaction of the T-shaped ligand (4 - 3'-pyridyl-,6 - 4'-carboxylphenyl)picolinic acid (H2L) with Co(NO₃)₂·6H₂O via a solvothermal process. Fluorescence spectroscopy revealed that the fluorescence emission of the CPs originates from the ligand, indicating their potential application as blue fluorescence materials. Subsequently, we encapsulated these CPs with hyaluronic acid (HA) and carboxymethyl chitosan (CMCS) hydrogels to create two types of metal gel particles carrying spironolactone (HA/CMCS-CPs@spironolactone). SEM and TEM analyses showed that the material consists of tightly stacked sheet-like structures with an average size of approximately 100 nm. Thermogravimetric analysis (TGA) indicated that the material begins to decompose at around 115 °C, demonstrating good thermal stability. We assessed the inhibitory effects of these materials on oxidative stress induced by PCOS. The results showed that both types of spironolactone-loaded metal gel particles significantly reduced malondialdehyde (MDA) levels, particularly the particles constructed with CP2. HA/CMCS-CP1@spironolactone reduced MDA levels by approximately 17% and 46% at low and high concentrations, respectively, while HA/CMCS-CP2@spironolactone decreased MDA levels by about 55% and 39% at high and low concentrations, respectively. Therefore, the novel drug delivery system reported in this study has the potential to become a safe and effective option for the localized treatment of PCOS.

Advances in porphyrin chemistry have provided exciting technologies in the field of optical biosensing. Herein, we have synthesized 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) and porous Zn_0.1Co₂O₄ nanorods using a simple one-pot hydrothermal method. The obtained TCPP- Zn_0.1Co₂O₄ composite was then used for the development of a novel optical sensor for the determination of uric acid (UA), which is an important biomarker in human urine, serum or saliva for the clinical diagnosis of hyperuricemia and hypouricemia, etc. TCPP-Zn_0.1Co₂O₄ composite was characterized using SEM, TEM, EDAX, PXRD, FT-IR, UV-Visible, and NMR spectroscopic techniques. The fluorescence emission spectral analysis of TCPP-Zn_0.1Co₂O₄ was then investigated for potential applications in the detection of uric acid via the fluorescence quenching mechanism. The designed sensor showed a linear response towards the uric acid in the concentration range of 0.99 to 5.2 nM. The optical sensor exhibits a sensitive response to uric acid with a detection limit of 0.015 nM. The sensor was employed to quantify UA in spiked human urine samples and artificial urine with satisfactory results.

A simple and facile microwave-assisted method was developed for the synthesis of highly fluorescent silver-nanoparticles (Ag-NPs). The synthesis of silver-nanoparticles depends on a redox reaction between silver nitrate and ascorbic acid using chitosan as a stabilizing agent. The produced Ag-NPs were characterized using Zeta potential and transmission electron microscope micrograph where they are spherical in shape with smooth surface morphology and size of 26.81 ± 2.2 nm. Favipiravir (FAV) was found to cause an obvious enhancement in the fluorescence of Ag-NPs; hence, they were used for its spectrofluorimetric estimation. The fluorescence intensity was measured at 430 nm after excitation at 360 nm. Under optimum conditions, a good linear relationship was accomplished between the FAV concentration and the fluorescence intensity in a range of (5.0-200.0) ng/mL with a limit of detection of 1.59 ng/mL. The method was successfully applied for the assay of the drug in its commercial tablets and spiked human plasma samples, and the results obtained were satisfactory.

In this study, a novel fluorescent probe for the rapid and highly selective detection of Fe^3 + based on biomass carbon dots (b-CDs) was developed. The b-CDs were obtained via one-step hydrothermal synthesis by utilizing laurel fallen leaves. And the as-synthesized b-CDs were applied for sensing Fe³⁺ based on fluorescence (FL) quenching effect both in water and phosphate buffer solution (PBS) with a wide linear range from 1 µM to 300 µM, the detection limits (LODs) respectively to be 0.34 µM in water and 0.48 µM in PBS solution. The FL intensity of b-CDs was quenched fleetly within 1 min after adding Fe³⁺. The sensing mechanism of the b-CDs + Fe³⁺ system can be attributed to the internal filtration effect (IFE) mechanism and the electron transfer (ET) between b-CDs and Fe³⁺ in water, and only the IFE mechanism in PBS solution based on multiple experimental evidences. Moreover, the as-proposed probe was successfully adopted for monitoring Fe³⁺ in lake water and tap water samples. This research shows some merits of economic, simplicity, green, high selectivity, and quick response for Fe³⁺ determination, and provides an approach for the water quality monitoring of Fe³⁺ and the effective utilization of waste biological materials.