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1.
J Chem Phys ; 160(15)2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38624117

RESUMO

Bio-templated luminescent noble metal nanoclusters (NCs) have attracted great attention for their intriguing physicochemical properties. Continuous efforts are being made to prepare NCs with high fluorescence quantum yield (QY), good biocompatibility, and tunable emission properties for their widespread practical applications as new-generation environment-friendly photoluminescent materials in materials chemistry and biological systems. Herein, we explored the unique photophysical properties of silver nanoclusters (AgNCs) templated by cytosine-rich customized hairpin DNA. Our results indicate that a 36-nucleotide containing hairpin DNA with 20 cytosine (C20) in the loop can encapsulate photostable red-emitting AgNCs with an absolute QY of ∼24%. The luminescent properties in these DNA-templated AgNCs were found to be linked to the coupling between the surface plasmon and the emitter. These AgNCs exhibited excellent thermal sensitivity and were employed to produce high-quality white light emission with an impressive color rendering index of 90 in the presence of dansyl chloride. In addition, the as-prepared luminescent AgNCs possessing excellent biocompatibility can effectively mark the nuclear region of HeLa cells and can be employed as a luminescent probe to monitor the cellular dynamics at a single molecular resolution.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Humanos , Prata/química , Citosina/química , Células HeLa , DNA/química , Replicação do DNA , Nanopartículas Metálicas/química , Espectrometria de Fluorescência/métodos , Técnicas Biossensoriais/métodos
2.
Sci Rep ; 14(1): 8493, 2024 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605135

RESUMO

This study involved the production of 20 biochar samples derived from secondary medicinal residues of Snow Lotus Oral Liquid, processed within the temperature range of 200-600 °C. Additionally, four medicinal residues, including dissolved organic matter (DOM), from 24 samples obtained using the shaking method, served as the primary source material. The investigation focused on two key factors: the modifier and preparation temperature. These factors were examined to elucidate the spectral characteristics and chemical properties of the pharmaceutical residues, biochar, and DOM. To analyze the alterations in the spectral attributes of biochar and medicinal residues, we employed near-infrared spectroscopy (NIR) in conjunction with Fourier-infrared one-dimensional and two-dimensional correlation spectroscopy. These findings revealed that modifiers enhanced the aromaticity of biochar, and the influence of preparation temperature on biochar was diminished. This observation indicates the stability of the aromatic functional group structure. Comparative analysis indicated that Na2CO3 had a more pronounced structural effect on biochar, which is consistent with its adsorption properties. Furthermore, we utilized the fluorescence indices from UV-visible spectroscopy and excitation-emission-matrix spectra with the PARAFAC model to elucidate the characteristics of the fluorescence components in the DOM released from the samples. The results demonstrated that the DOM released from biochar primarily originated externally. Aromaticity reduction and increased decay will enhance the ability of the biochar to bind pollutants. Those results confirmed the link between the substantial increase in the adsorption performance of the high-temperature modified charcoal in the previous study and the structural changes in the biochar. We investigated the structural changes of biochar and derivative DOM in the presence of two perturbing factors, modifier and preparation temperature. Suitable modifiers were selected. Preparation for the study of adsorption properties of snow lotus medicinal residues.


Assuntos
Carvão Vegetal , Lotus , Carvão Vegetal/química , Matéria Orgânica Dissolvida , Temperatura , Espectrometria de Fluorescência/métodos , Substâncias Húmicas/análise
3.
Luminescence ; 39(4): e4741, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38605268

RESUMO

In the present study, a first validated and green spectrofluorimetric approach for its assessment and evaluation in different matrices was investigated. After using an excitation wavelength of 345 nm, Roxadustat (ROX) demonstrates a highly native fluorescence at an emission of 410 nm. The influences of experimental factors such as pH, diluting solvents, and different organized media were tested, and the most appropriate solvent choice was ethanol. It was confirmed that there was a linear relationship between the concentration of ROX and the relative fluorescence intensity in the range 60.0-1000.0 ng ml-1, with the limit of detection and limit of quantitation, respectively, being 17.0 and 53.0 ng ml-1. The mean recoveries % [±standard deviation (SD), n = 5] for pharmaceutical preparations were 100.11% ± 2.24%, whereas for plasma samples, they were 100.08 ± 1.08% (±SD, n = 5). The results obtained after the application of four greenness criteria, Analytical Eco-Scale metric, NEMI, GAPI, and AGREE metric, confirmed its eco-friendliness. In addition, the whiteness meter (RGB12) confirmed its level of sustainability. The International Council for Harmonisation (ICH) criteria were used to verify the developed method through the study in both spiked plasma samples and content uniformity evaluation. An appropriate standard for various applications in industry and quality control laboratories was developed.


Assuntos
Hematínicos , Humanos , Limite de Detecção , Espectrometria de Fluorescência/métodos , Eritropoese , Concentração de Íons de Hidrogênio , Solventes/química , Comprimidos/química , Isoquinolinas
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 314: 124224, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38574611

RESUMO

Overuse of doxycycline (DOXY) can cause serious problems to human health, environment and food quality. So, it is essential to develop a new sensing methodology that is both sensitive and selective for the quantitative detection of DOXY. In our current research, we synthesized a simple fluorescent probe 4,4'-bis(benzyloxy)-1,1'-biphenyl (BBP) for the highly selective detection of doxycycline by through fluorescence spectroscopy. The probe BBP displayed ultra-sensitivity towards doxycycline due to Forster resonance energy transfer (FRET). Fluorescence spectroscopy, density functional theory (DFT), 1H NMR titration, UV-Vis, and Job's plot were used to confirm the sensing mechanism. The charge transfer between the probe and analyte was further examined qualitatively by electron density differences (EDD) and quantitively by natural bond orbital (NBO) analyses. Whereas the non-covalent nature of probe BBP towards DOXY was verified by theoretical non-covalent interaction (NCI) analysis as along with Bader's quantum theory of atoms in molecules (QTAIM) analysis. Furthermore, probe BBP was also practically employed for the detection of doxycycline in fish samples, pharmaceutical wastewater and blood samples.


Assuntos
Doxiciclina , Corantes Fluorescentes , Animais , Humanos , Corantes Fluorescentes/química , Espectrometria de Fluorescência/métodos , Transferência Ressonante de Energia de Fluorescência , Espectroscopia de Ressonância Magnética
5.
Luminescence ; 39(4): e4742, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38637644

RESUMO

A simple, rapid, and low-cost technique was developed to allow reliable analysis of the anti-hepatitis C drug sofosbuvir in bulk, tablet form, and spiked human plasma. This method depends on the ability of sofosbuvir to quench the fluorescence of the newly synthesized 2-amino-3-cyano-4,6-dimethylpyridine (reagent 3). Elemental analysis and spectral data were used to validate the structure of the synthesized reagent. The newly synthesized reagent exhibited a satisfactory level of fluorescence emission at 365 nm after excitation at 247 nm. All experimental variables that might affect the quenching process were analyzed and optimized. Linearity, range, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ) were all validated in accordance with the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. The concentration range was shown to be linear between 0.1 and 1.5 µg/mL. The technique was effectively utilized for sofosbuvir analysis in both its tablet dosage form and spiked human plasma, with mean percentage recoveries of 100.13 ± 0.35 and 94.26 ± 1.69, respectively.


Assuntos
Corantes Fluorescentes , Sofosbuvir , Humanos , Espectrometria de Fluorescência/métodos , Comprimidos
6.
Anal Chim Acta ; 1304: 342579, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38637044

RESUMO

Plasmon enhanced fluorescent (PEF) with more "hot spots" play a critical role in signal amplified technology to avoid the intrinsic limitation of fluorophore which ascribed to a strong electromagnetic field at the tip structure. However, application of PEF technique to obtain a highly sensitive analysis of medicine was still at a very early stage. Herein, a simple but versatile Ag nanocubes (Agcubes)-based PEF sensor combined with aptamer (Agcubes@SiO2-QDs-Apt) was proposed for highly sensitive detection of berberine hydrochloride (BH). The distance between the plasma Agcubes and the red-emitted CdTe quantum dots (QDs) were regulated by the thickness of silica spacer. The three-dimensional finite-difference time-domain (3D-FDTD) simulation further revealed that Agcubes have a higher electromagnetic field than Ag nanospheres. Compared with PEF sensor, signal QDs-modified aptamer without Agcubes (QDs-Apt) showed a 10-fold higher detection limit. The linear range and detection limit of the Agcubes@SiO2-QDs-Apt were 0.1-100 µM, 87.3 nM, respectively. Furthermore, the PEF sensor was applied to analysis BH in the berberine hydrochloride tablets, compound berberine tablet and urine with good recoveries of 98.25-102.05%. These results demonstrated that the prepared PEF sensor has great potential for drug quality control and clinical analysis.


Assuntos
Aptâmeros de Nucleotídeos , Berberina , Compostos de Cádmio , Pontos Quânticos , Fluorescência , Pontos Quânticos/química , Compostos de Cádmio/química , Dióxido de Silício , Telúrio/química , Espectrometria de Fluorescência/métodos , Aptâmeros de Nucleotídeos/química , Limite de Detecção
7.
Luminescence ; 39(3): e4728, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38516711

RESUMO

A novel spectrofluorimetric method has been developed for determination of antazoline (ANT) and tetryzoline (TET) in their pharmaceutical formulation. A combined application of synchronous spectrofluorimetry and second derivative mathematical treatment was developed. The proposed method depends on reacting the cited drugs with dansyl chloride (DNS-Cl) being a suitable derivatizing agent generating highly fluorescent derivatives measured at emission wavelengths of 703.0 and 642.0 nm after excitation wavelengths of 350.0 and 320.0 nm for ANT and TET, respectively. The joint use of synchronous spectrofluorimetry with second derivative mathematical treatment is for the first time to be developed and optimized in aid of using fluorescence data manager software generating second derivative peak amplitudes at 556.5 nm for ANT and 516.7 nm for TET. Linear responses have been represented over a wide range of concentration (0.5-12.0 µg/mL for ANT and 0.5-10.0 µg/mL for TET). Additionally, statistical comparison of the developed method with the official ones has been carried out where no significant difference was found. Additionally, greenness profile assessment was accomplished by means of four metric tools. Indeed, the method developed is found to be precise, sensitive, and discriminating to assess the cited drugs for regular analysis.


Assuntos
Antazolina , Antazolina/análise , Espectrometria de Fluorescência/métodos , Imidazóis
8.
Int J Biol Macromol ; 265(Pt 2): 131111, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38522700

RESUMO

Iron ions play a crucial role in the environment and the human body. Therefore, developing an effective detection method is crucial. In this paper, we report CNS2, a chitosan-based fluorescent probe utilizing naphthalimide as a fluorophore. CNS2 is designed to "quench" its own yellow fluorescence through the specific binding of compounds containing enol structures to Fe3+. Studying the fluorescence lifetime of CNS2 in the presence or absence of Fe3+ reveals that the quenching mechanism is static. The presence of multiple recognition sites on the chitosan chain bound to Fe3+ gave CNS2 rapid recognition (1 min) and high sensitivity, with a detection limit as low as 0.211 µM. Moreover, the recognition of Fe3+ by CNS2 had a good specificity and was not affected by interferences. More importantly, in this study, CNS2 was successfully utilised to prepare fluorescent composite membranes and to detect Fe3+ in real water samples and a variety of food samples. The results show that the complex sample environment still does not affect the recognition of Fe3+ by CNS2. All the above experiments obtained more satisfactory results, which provide strong support for the detection of Fe3+ by the probe CNS2 in practical applications.


Assuntos
Quitosana , Corantes Fluorescentes , Humanos , Corantes Fluorescentes/química , Água , Quitosana/química , Ferro/química , Fluorescência , Espectrometria de Fluorescência/métodos
9.
Chemosphere ; 355: 141826, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38552805

RESUMO

Recent studies have increasingly focused on the occurrence of plastic leachate and its impacts on aquatic ecosystems. Nonetheless, the environmental fate of this leachate in the presence of abundant natural organic matter (NOM)-a typical scenario in environments contaminated with plastics-remains underexplored. This study investigates the photo-induced leaching behaviors of dissolved organic matter (DOM) from terrestrial-sourced particles (forest soil and leaf litter) and microplastics (MPs), specifically polystyrene (PS) and polyvinyl chloride (PVC), over a two-week period. We also examined the biodegradability and spectroscopic characteristics of the leached DOM from both sources. Our results reveal that DOM from microplastics (MP-DOM) demonstrates more persistent leaching behavior compared to terrestrial-derived DOM, even with lesser quantities per unit of organic carbon. UV irradiation was found to enhance DOM leaching across all particle types. However, the photo-induced leaching behaviors of fluorescent components varied with the particle type. The MP group exhibited a broader range and higher biodegradability (ranging from 19.7% to 61.6%) compared to the terrestrial-sourced particles (ranging from 3.7% to 16.5%). DOM leached under UV irradiation consistently showed higher biodegradability than that under dark conditions. Furthermore, several fluorescence characteristics of DOM, such as the protein/phenol-like component (%C2), terrestrial humic-like component (%C3), and humification index (HIX)-traditionally used to indicate the biodegradability of natural organic matter-were also effective in assessing MP-DOM (with correlation coefficients R2 = 0.6055 (p = 0.003), R2 = 0.5389 (p = 0.007), and R2 = 0.4640 (p = 0.015), respectively). This study provides new insights into the potential differences in environmental fate between MP-DOM and NOM in aquatic environments heavily contaminated with MPs.


Assuntos
Microplásticos , Plásticos , Matéria Orgânica Dissolvida , Ecossistema , Solo/química , Substâncias Húmicas/análise , Espectrometria de Fluorescência/métodos
10.
Anal Chem ; 96(13): 5331-5339, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38498948

RESUMO

At present, there is a lack of sufficiently specific laboratory diagnostic indicators for schizophrenia. Serum homocysteine (Hcy) levels have been found to be related to schizophrenia. Cysteine (Cys) is a demethylation product in the metabolism of Hcy, and they always coexist with highly similar structures in vivo. There are few reports on the use of Cys as a diagnostic biomarker for schizophrenia in collaboration with Hcy, mainly because the rapid, economical, accurate, and high-throughput simultaneous detection of Cys and Hcy in serum is highly challenging. Herein, a click reaction-based surface-enhanced Raman spectroscopy (SERS) sensor was developed for simultaneous and selective detection of Cys and Hcy. Through the efficient and specific CBT-Cys click reaction between the probe containing cyan benzothiazole and Cys/Hcy, the tiny methylene difference between the molecular structures of Cys and Hcy was converted into the difference between the ring skeletons of the corresponding products that could be identified by plasmonic silver nanoparticle enhanced molecular fingerprint spectroscopy to realize discriminative detection. Furthermore, the SERS sensor was successfully applied to the detection in related patient serum samples, and it was found that the combined analysis of Cys and Hcy can improve the diagnostic accuracy of schizophrenia compared to a single indicator.


Assuntos
Nanopartículas Metálicas , Esquizofrenia , Humanos , Cisteína/química , Células HeLa , Esquizofrenia/diagnóstico , Corantes Fluorescentes/química , Prata , Espectrometria de Fluorescência/métodos , Homocisteína , Glutationa/análise
11.
Int J Mol Sci ; 25(6)2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38542159

RESUMO

This article discusses the design and analysis of a new chemical chemosensor for detecting mercury(II) ions. The chemosensor is a hydrazone made from 4-methylthiazole-5-carbaldehyde and fluorescein hydrazide. The structure of the chemosensor was confirmed using various methods, including nuclear magnetic resonance spectroscopy, infrared spectroscopy with Fourier transformation, mass spectroscopy, and quantum chemical calculations. The sensor's ability in the highly selective and sensitive discovery of Hg2+ ions in water was demonstrated. The detection limit for mercury(II) ions was determined to be 0.23 µM. The new chemosensor was also used to detect Hg2+ ions in real samples and living cells using fluorescence spectroscopy. Chemosensor 1 and its complex with Hg2+ demonstrate a significant tendency to enter and accumulate in cells even at very low concentrations.


Assuntos
Mercúrio , Metais Pesados , Poluentes Químicos da Água , Fluoresceína , Água , Corantes Fluorescentes/química , Poluentes Químicos da Água/análise , Mercúrio/análise , Espectrometria de Fluorescência/métodos
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 313: 124110, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38452462

RESUMO

A catalytic hairpin self-assembly (CHA) amplification method was developed for CAP detection based on cross-shaped DNA and UiO-66. MOF was used to quench the fluorescent signal of FAM labeled DNA. Cross-shaped DNA with four fluorophore group (FAM) was utilized to enhance the fluorescent intensity. CAP could open hairpin structure of H-apt and induce CHA reaction. The product of CHA hybridized with cross-shaped DNA, resulting its leaving from the surface of UiO-66 and recovery of fluorescent signal. The limit of detection (LOD) was low to 0.87 pM. This method had been successfully applied for the detection of CAP in actual samples. Importantly, the high sensitivity was attributed to the great amplification efficiency of CHA, strong fluorescent intensity of cross-shaped DNA structure and great fluorescent quenched efficiency of UiO-66.


Assuntos
Técnicas Biossensoriais , DNA Catalítico , Estruturas Metalorgânicas , Ácidos Ftálicos , Cloranfenicol , DNA/química , Espectrometria de Fluorescência/métodos , Limite de Detecção , Técnicas Biossensoriais/métodos , DNA Catalítico/química
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 313: 124107, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38452459

RESUMO

The proposed research adheres to a certain methodology to ensure that the technique used for analyzing the centrophenoxine drug is sustainable and green. It is important to highlight that several tools that have been recently developed were utilized as potential indicators of environmental sustainability and applicability. The present research presents a novel and entirely innovative method utilizing ultrasensitive spectrofluorimetry for the detection of centrophenoxine (CPX) drug. The employed methodology in this study involved the utilization of one-step, one-pot, and direct spectrofluorimetric technique, which was found to be both efficient and environmentally sustainable in the validation and assessment of the drug. Simply, when CPX and erythrosine B reagent were combined in an acidic environment, the highly resonance Rayleigh scattering product was immediately produced. The sensitivity limits were observed to be within the range of 15-47 ng mL-1, whereas the linearity was assessed to be in the range of 50-2000 ng mL-1. The optimal settings for all modifiable parameters of the system were ascertained through an analysis of centrophenoxine-erythrosine B complexes. Moreover, the system demonstrated compliance with International Council for Harmonization (ICH) specifications without encountering any issues. The suggested process was then rated on different recent environmental safety measuring metrics to see how good it was for the environment. Fortunately, the WAC standards that combine ecological and functional elements utilizing the Green/Red/Blue (RGB 12) design also acclaimed the current analytical technique as a white one. Additionally, a new applicability evaluation tool (BAGI) was employed to estimate the practicability of the planned method in the analytical chemistry field.


Assuntos
Eritrosina , Nootrópicos , Eritrosina/química , Meclofenoxate , Antioxidantes , Espalhamento de Radiação , Espectrometria de Fluorescência/métodos
14.
Anal Methods ; 16(13): 1934-1947, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38497319

RESUMO

Cation and anion sensing is vital owing to their universal dispersion in ecosystems and biological functions. It has been shown that fluorescent receptors based on organic platforms are efficient for detecting a number of ions and have many advantages such as low cost, superior sensitivity and simplicity in installation. This study demonstrates the design and synthesis of a novel receptor (E)-3-[(3,5-di-tert-butyl-2-hydroxybenzylidene)amino]-2-(pyren-1-yl)-2,3-dihydroquinazolin-4(1H)-one (DTQ) for the rapid recognition of Zn(II) ions. DTQ exhibited a significant fluorometric "turn-on" characteristic towards Zn(II) at λmax 444 nm in aqueous acetonitrile by inhibiting the photo-induced electron transfer (PET) and -CN- process. The ESI-MS analysis and Job's plot experimental results confirmed stoichiometric 1 : 1 complex formation between DTQ and Zn(II). Fluorometric investigations revealed the detection limit and association constant of DTQ towards Zn(II), which were found to be 13.4 nM and 1.47 × 105 M-1, respectively. DTQ was employed to sense Zn(II) on low-cost test strips. The present research findings imply that DTQ can function as an effective sensor for Zn(II).


Assuntos
Ecossistema , Corantes Fluorescentes , Quinazolinas , Espectrometria de Fluorescência/métodos , Zinco/análise , Imagem Óptica/métodos , Íons
15.
Luminescence ; 39(3): e4699, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38494638

RESUMO

A simple naphthalimide-based fluorescent probe was designed and synthesized for the determination of mercury ion (Hg2+ ). The probe showed a noticeable fluorescence quenching response for Hg2+ . When added with Hg2+ , the fluorescence intensity of the probe at 560 nm was remarkably decreased with the color changed from yellow to colorless under ultraviolet (UV) light. The probe had a notable selectivity and sensitivity for Hg2+ and displayed an excellent sensing performance when detecting Hg2+ at low concentration (19.5 nM). The binding phenomenon between the probe and Hg2+ was identified by Job's method and high-resolution mass spectrometry (HRMS). Moreover, the probe was not only utilized to identify Hg2+ in real samples with satisfactory results (92.00%-110.00%) but also was successfully used for bioimaging in cells and zebrafish. The recognition mechanism has been verified by transmission electron microscopy (TEM) for the first time. All the results showed that the probe could be used as a potent useful tool for detection of Hg2+ .


Assuntos
Corantes Fluorescentes , Mercúrio , Animais , Corantes Fluorescentes/química , Peixe-Zebra , Naftalimidas/química , Espectrometria de Fluorescência/métodos , Mercúrio/análise
16.
J Phys Chem B ; 128(11): 2640-2651, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38452253

RESUMO

2-Aminopurine (2AP) is the most widely used fluorescent nucleobase analogue in DNA and RNA research. Its unique photophysical properties and sensitivity to environmental changes make it a useful tool for understanding nucleic acid dynamics and DNA-protein interactions. We studied the effect of ions present in commonly used buffer solutions on the excited-state photophysical properties of 2AP. Fluorescence quenching was negligible for tris(hydroxymethyl)aminomethane (TRIS), but significant for phosphate, carbonate, 3-(N-morpholino) propanesulfonic acid (MOPS), and 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffers. Results indicate that the two tautomers of 2AP (7H, 9H) are quenched by phosphate ions to different extents. Quenching by the H2PO4- ion is more pronounced for the 7H tautomer, while the opposite is true for the HPO42- ion. For phosphate ions, the results of the time-resolved fluorescence study cannot be explained using a simple collisional quenching mechanism. Instead, results are consistent with transient interactions between 2AP and the phosphate ions. We postulate that excited-state interactions between the 2AP tautomers and an H-bond acceptor (phosphate and carbonate) result in significant quenching of the singlet-excited state of 2AP. Such interactions manifest in biexponential fluorescence intensity decays with pre-exponential factors that vary with quencher concentration, and downward curvatures of the Stern-Volmer plots.


Assuntos
2-Aminopurina , DNA , 2-Aminopurina/química , Fluorescência , DNA/química , Carbonatos , Fosfatos , Espectrometria de Fluorescência/métodos
17.
Luminescence ; 39(3): e4712, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38481369

RESUMO

In this study, a novel fluorescent chemosensor 1 based on chromone-3-carboxaldehyde Schiff base was synthesized and featured through nuclear magnetic resonance (NMR) and mass spectra. Spectroscopic investigation indicated that the fluorescent sensor showed high selectivity toward Zn2+ over other metal ions and that the detection limit of 1 could reach 10-7  M. These indicated that 1 acted as a highly selective and sensitive fluorescence chemosensor for Zn2+ .


Assuntos
Corantes Fluorescentes , Bases de Schiff , Espectrometria de Fluorescência/métodos , Corantes Fluorescentes/química , Bases de Schiff/química , Cromonas , Zinco
18.
Luminescence ; 39(3): e4696, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38494193

RESUMO

Antidepressants can cause sexual dysfunction side effects, necessitating the co-administration of phosphodiesterase type 5 inhibitors. The simultaneous determination of these drugs in biological fluids is critical for therapeutic drug monitoring. For the first time, two binary mixtures containing duloxetine with either avanafil or tadalafil were estimated utilizing simple green spectrofluorimetric methods without the need for a previous separation step. The study was based on first derivative synchronous spectrofluorimetry in ethanol using a change in wavelength difference (∆λ) of 20 and 25 nm for the first and second combinations, respectively. Duloxetine and avanafil were estimated at 297.7 and 331 nm in their binary mixture, while duloxetine and tadalafil were determined at 290.3 and 297.7 nm, respectively. The linearity was achieved over the ranges of 0.1-1.5 µg mL-1 for both duloxetine and avanafil and 0.01-0.40 µg mL-1 for tadalafil, with limits of detection of 0.013, 0.022, and 0.004 µg mL-1 for duloxetine, avanafil, and tadalafil, respectively. Successful application of the developed approaches was accomplished for the estimation of the two mixtures in dosage forms as well as human plasma with excellent percentage recoveries (96-103.75% in plasma), which supports their suitability for use in quality control laboratories and pharmacokinetic studies. Moreover, the adopted approaches' greenness was evidenced by applying three tools.


Assuntos
Pirimidinas , Humanos , Tadalafila , Cloridrato de Duloxetina , Preparações Farmacêuticas , Espectrometria de Fluorescência/métodos
19.
Sci Rep ; 14(1): 6464, 2024 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-38499633

RESUMO

The amino acids tryptophan, tyrosine, and phenylalanine have been extensively used for different label-free protein studies, based on the intensity, lifetime, wavelength and/or polarization of their emitted fluorescence. Similar to most fluorescent organic molecules, these amino acids can undergo transitions into dark meta-stable states, such as triplet and photo-radical states. On the one hand, these transitions limit the fluorescence signal, but they are also highly environment-sensitive and can offer an additional set of parameters, reflecting interactions, folding states, and immediate environments around the proteins. In this work, by analyzing the average intensity of tyrosine emission under different excitation modulations with the transient state monitoring (TRAST) technique, we explored the photo physics of tyrosine as a basis for such environment-sensitive readouts. From how the dark state transitions of tyrosine varied with excitation intensity and solvent conditions we first established a photophysical model for tyrosine. Next, we studied Calmodulin (containing two tyrosines), and how its conformation is changed upon calcium binding. From these TRAST experiments, performed with 280 nm time-modulated excitation, we show that tyrosine dark state transitions clearly change with the calmodulin conformation, and may thus represent a useful source of information for (label-free) analyses of protein conformations and interactions.


Assuntos
Calmodulina , Tirosina , Tirosina/química , Calmodulina/metabolismo , Espectrometria de Fluorescência/métodos , Conformação Proteica , Triptofano/química , Corantes
20.
Luminescence ; 39(3): e4711, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38501299

RESUMO

Ambroxol hydrochloride (AMX) and guaifenesin (GFN) are approved drugs utilized to treat coughs through their potent mucolytic and expectorant properties. Due to their massive, combined administration in many illnesses, there is a persistent need for their concurrent estimation in different pharmaceutical formulations. Two sensitive, environmentally friendly spectrofluorimetric methods were developed. AMX was determined using the first method (I) without interference from GFN. This method depends on the quenching of Erythrosine B (EB) native fluorescence at 552 nm after excitation at 527 nm due to the formation of a non-fluorescent AMX-EB ion-pair complex in Britton-Robinson buffer (BRB) solution pH (3.5). The concentration plot is linear over the 0.25-5.0 µg/mL range, with a mean percent found value of 99.74%. Method (II) depends on measuring the native fluorescence of aqueous GFN solution at two analytical wavelengths, either 300 or 600 nm, after excitation at 274 nm. Relative fluorescence intensity (RFI)-concentration plots are linear over the ranges of 0.02-0.5 and 0.1-2.0 µg/ml, with mean percent found at 99.96% and 99.91% at dual wavelengths, respectively. The proposed methods were successfully applied to assay both drugs in raw materials and different single and combined pharmaceutical formulations. These methods have been thoroughly validated following International Committee on Harmonisation (ICH) guidelines. National Environmental Methods Index, Analytical Eco-Scale, and Green Analytical Procedure Index were used to prove greenness, thereby enhancing their applicability. The proposed techniques provide straightforward, precise, and cost-effective solutions for routine formulation analysis in quality control laboratories.


Assuntos
Ambroxol , Guaifenesina , Guaifenesina/análise , Espectrometria de Fluorescência/métodos , Composição de Medicamentos , Preparações Farmacêuticas
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