Luminescence最新文献

The current research discusses a simple, sensitive, and practical spectrofluorimetric method for Modafinil (MDF) analysis. MDF can improve the fatigue symptoms associated with amyotrophic lateral sclerosis. MDF's aliphatic primary amide moiety can undergo base-catalyzed condensation with o-phthalaldehyde to give a highly fluorescent isoindoline derivative measured at 445 nm using synchronous spectrofluorimetry with Δλ of 110 nm. Different factors were studied using a two-level factorial design to reach the optimum conditions for the analysis. The method validation was carried out following the International Conference on Harmonization guidelines. The calibration curve was established to illustrate how relative fluorescence intensity varies with MDF concentration, and linearity was attained over the range of 10–7000 ng mL⁻¹, with an average recovery of 100.51% ± 0.91%. The limit of detection (LOD) was determined to be 3.21 ng mL⁻¹ while the quantitation limit (LOQ) was found to be 9.74 ng mL⁻¹. The developed method demonstrated its effectiveness in determining MDF in tablets and spiked human plasma with recoveries of 100.43% ± 0.16 and 96.07% ± 1.55, respectively. MoGAPI, AGREE, and BAGI assessments yielded scores of 72, 0.62, and 70, respectively. The results show that the method is user-friendly and can be used in routine applications.

A novel, sensitive, and eco-friendly derivatization-free synchronous fluorescence spectroscopic method was developed and optimized for the simultaneous quantification of enzalutamide and darolutamide. A quality-by-design approach was adopted using a screening design followed by Box–Behnken optimization to investigate the effects of photomultiplier tube voltage, solvent, excitation, and emission slit width on fluorescence response. The determination of first-derivative synchronous spectrofluorimetric scan was done at ∆λ = 50 nm, where amplitudes were recorded at 626 nm for darolutamide and 522 nm for enzalutamide without any interference. The method was validated per ICH Q2(R2) guidelines, showing excellent linearity in ranges of 1.0–12.0 μg/mL for enzalutamide and darolutamide with the LOQ value of < 1.0 μg/mL for both drugs. The validated method was successfully applied to pharmaceutical formulations to determine cleaning residues of enzalutamide and darolutamide. The method was applied at the lower level of 2.0 μg/mL for cleaning the residues from stainless-steel surfaces in a manufacturing environment with promising recovery results from rinse and swab methods. The method was evaluated for analytical greenness metrics using Analytical Green Star Area and Multicolor Assessment tools. This study represents the first report of a synchronous fluorimetric method for this drug pair and its usage in the pharmaceutical cleaning process.

Cervical cancer remains a major global health concern, contributing significantly to cancer-related mortality. In recent years, the biogenic synthesis of nanoparticles has emerged as a promising approach for cancer therapy, advancing targeted drug delivery and therapeutic applications. This study focuses on the phytochemical composition, synthesis, characterization, and cytotoxicity assay of silver nanoparticles (AgNPs) derived from the green seaweed Caulerpa peltata, which were synthesized by reacting 1 mM silver nitrate with the ethanolic extract of C. peltata under dark conditions, with gentle agitation for 1–10 h. The formation of AgNPs and the involvement of biomolecules in the synthesis process were confirmed through UV-visible spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive x-ray spectroscopy, and scanning electron microscopy. The cytotoxic potential of the biosynthesized AgNPs was evaluated using the MTT (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) assay, demonstrating significant inhibition of cervical cancer cell growth. The determined IC₅₀ value of 500 μg/mL was only 25.71%, indicating a dose- and time-dependent reduction in cell viability. These findings highlight the potential of C. peltata–mediated AgNPs as an eco-friendly alternative for anticancer therapy, particularly in the treatment of cervical cancer.

A thermally stable Eu³⁺-activated Na₂CaMg(PO₄)₂ (NCMP) phosphor was synthesized via a conventional solid-state reaction method for potential white LED applications. The brianite phase of NCMP was confirmed using PXRD, while its morphology and elemental composition were studied through FE-SEM and EDAX mapping. Diffuse reflectance spectra revealed wide band gaps of 3.87 eV (pure) and 3.99 eV (9 mol% Eu³⁺), with refractive indices of 2.01 and 2.02, respectively. Under 396 nm excitation, strong red emission at 616 nm was observed, attributed to a dipole–dipole transition. Judd–Ofelt analysis indicated a higher Ω₂ than Ω₄, suggesting strong covalent interaction between Eu³⁺ and ligands. The CIE chromaticity coordinates confirmed a red hue with high color purity (91.17%) and warm color temperature. The photoluminescence lifetime decreased with higher doping, whereas thermal stability was maintained at 74%. These findings demonstrate the suitability of NCMP:9 mol% Eu³⁺ phosphors for solid-state lighting and multifunctional applications.

Halide-based double perovskites are appealing choices for optoelectronic devices due to their adjustable energy gaps and enhanced structural stability compared to conventional perovskites. They are also strong candidates for efficient energy conversion systems due to their remarkable thermoelectric properties. In the present study, we used first-principles calculations and extensively examined the structural, electronic, optical, and transport features of cubic-phase Cs₂InAgX₆ (X = Cl, F) double perovskites. The TB-mBJ potential revealed semiconducting nature with direct band gaps of 2.53 eV for Cs₂InAgCl₆ and 4.39 eV for Cs₂InAgF₆, respectively. Additionally, the optical response is studied to evaluate its possibilities in devices used in optoelectronics. Significant absorption exists in the ultraviolet range with the vital absorption peaks noticed between 8.0 and 13.0 eV. At 50 K, the ZT values were reported to be 0.99 for both materials. This study reveals that these materials are excellent choices for next-generation functional devices because of their remarkable optoelectronic and thermoelectric qualities.

Existing methods for AFZ estimation lacked sensitivity for picoscale detection in biological samples, faced matrix interferences, and used environmentally harmful solvents. A sensitive, selective, and eco-friendly microwave-assisted fluorodensitometric probe was developed for picoscale estimation of AFZ in pharmaceutical formulations and human plasma. The method utilized a microwave-assisted microlevel Hantzsch reaction for the generation of a fluorodensitometric probe for AFZ derivatization in the microenvironment of a silica plate. A design of experiments (DoE) approach was implemented using a Plackett–Burman design for risk assessment and a minimum run resolution IV design for response surface analysis. HPTLC–MS was used for the characterization of the fluorodensitometric probe generated by microwave-aided microlevel condensation of organic liquids and AFZ. The method demonstrated linearity in the range of 10–50 pg/band with high sensitivity (LOD: 3.0 pg/band, LOQ: 10.0 pg/band). Precision and accuracy were within acceptable limits. The method was successfully applied to pharmaceutical formulations and different plasma samples. The proposed method offers a sensitive, selective, and environmentally friendly approach for AFZ estimation at picoscale levels, adhering to white analytical chemistry principles and the QbD approach.

To meet the growing demand for sensing technologies, it is imperative to develop novel sensors with higher sensitivity, portability, and low cost. Conventional single-signal sensors suffer from limitations such as low sensitivity, narrow detection range, and susceptibility to false positives. Integrating two sensing signals into a single system to design dual-signal sensors effectively addresses these issues. Among optical sensors, fluorescence and colorimetric signals are the most well-developed and have been widely applied in food safety, environmental monitoring, and biomedical fields. Fluorescence/colorimetric dual-signal sensors not only combine the advantages of both modalities but also synergistically enhance detection accuracy, broaden the detection range, and improve flexibility, significantly boosting detection efficiency. In recent years, such sensors have undergone rapid development. This review focuses on the signal activation strategies and design principles of fluorescence/colorimetric dual-signal sensors, particularly the specific recognition mechanisms for diverse targets, aiming to provide insights for the design of next-generation sensors.

A novel salicylaldehyde-benzohydrazide–based fluorescent probe L was designed and synthesized. The probe displayed excellent specificity and sensitivity for Zn²⁺ detection in aqueous media (HEPES buffer, pH = 7.40), accompanied by a remarkable colorimetric fluorescence change from colorless to green under a 365 nm UV lamp. The detection mechanism of probe L for Zn²⁺ was elucidated by ¹H NMR, HRMS, and DFT calculation. Moreover, the probe was effectively applied in the detection of Zn²⁺ in both environmental samples and biological imaging in living cells.

Tartrazine (synthetic food dye) has been known to exert oxidative stress-related effects, yet its direct impact on antioxidant enzymes like catalase remains poorly understood. This study explores the interaction between tartrazine (synthetic dye) and catalase using various spectroscopic and in silico techniques. UV–visible as well as spectrofluorometric analysis revealed the formation of a catalase-tartrazine complex with a static mode of quenching. A moderate binding affinity ranging from 0.35 to 1.66 × 10⁴ M⁻¹ was calculated for the complex. Positive ΔH (23.72 kcal/mol) and ΔS (28.57–29.72 kcal/mol) with negative ΔG (−4.84 to −5.99 kcal/mol) suggest the binding process is endothermic and spontaneous, driven by a favorable entropy change. Circular dichroism (CD) indicates the percent α-helix in catalase decreased from 28.06% to 23.29% upon tartrazine binding, indicating some structural alterations. In turn, the catalase activity was decreased (60%) at a higher concentration (100 μM) of tartrazine. Molecular docking analysis identified several active site residues, including Met349, Gly352, Arg353, and Thr360, as key players in the binding process. Further, simulation studies demonstrated that the complex of tartrazine with catalase maintained stability in an aqueous environment. Our findings hinted that the use of additives should be cautious as they may compromise the antioxidant defense mechanisms critical to human health.

This work describes a novel Co²⁺ ion sensor 3-(2-(2-(4-nitrophenyl)-4,5-diphenyl-1H-imidazol-1-yl)thiazol-4-yl)-2H-chromen-2-one (NBIC) comprising imidazole and a coumarin-thiazole moiety. When Co²⁺ is present, NBIC shows a notable quenching of fluorescence at 450 nm as a result of complex formation. The limit of detection was found to be 7 μM under optimal conditions. It was discovered that the sensor was quite selective for Co²⁺ ions despite many competing ions. The chemosensor NBIC also exhibited colorimetric and fluorometric sensing ability with a visible colorimetric response to trifluoroacetic acid (TFA). The Job's plot validates the 1:1 binding stoichiometry between Co²⁺ and NBIC. Further, the study was also validated with zebrafish bioimaging studies.