Pub Date : 2025-04-18DOI: 10.1016/j.saa.2025.126272
Vladimir N. Morozov , Mikhail A. Klimovich , Maria A. Kolyvanova , Vladimir A. Kuzmin
Most of the studies on the interaction of fluorescent dyes with DNA have been performed under conditions radically different from those occurring in situ. Among others, this includes diluteness of experimental solutions, their homogeneity, and presence of a large amount of free water. To a certain extent, some model systems can help to approach the biological conditions. Thus, since some features of liquid-crystalline-like packaging of DNA were found in a number of living systems, to shed light on the behavior of Hoechst 33258 in biological-like conditions, we performed a detailed study of its properties in DNA-PEG mixtures, and, in particular, in the dispersed mesophases formed via polymer and salt induced (psi-) condensation. Being in complex with DNA, Hoechst 33258 shows a high sensitivity to the changes in osmotic conditions – the addition of PEG leads to a release of the dye molecules. However, this effect nonlinearly depends on osmolality. Individually, neither PEG nor NaCl at the studied concentrations significantly affect its complex with nucleic acid. The effect is caused precisely by their synergistic action. In cases of the dispersed systems formation, significant fraction of Hoechst 33258 molecules is retained within the resulting particles and is protected even from further increase in osmolality. This is partly due to competition between the processes of the dye releasing and formation of the dispersed particles.
{"title":"On the behavior of Hoechst 33258 in DNA-PEG mixtures","authors":"Vladimir N. Morozov , Mikhail A. Klimovich , Maria A. Kolyvanova , Vladimir A. Kuzmin","doi":"10.1016/j.saa.2025.126272","DOIUrl":"10.1016/j.saa.2025.126272","url":null,"abstract":"<div><div>Most of the studies on the interaction of fluorescent dyes with DNA have been performed under conditions radically different from those occurring <em>in situ</em>. Among others, this includes diluteness of experimental solutions, their homogeneity, and presence of a large amount of free water. To a certain extent, some model systems can help to approach the biological conditions. Thus, since some features of liquid-crystalline-like packaging of DNA were found in a number of living systems, to shed light on the behavior of Hoechst 33258 in biological-like conditions, we performed a detailed study of its properties in DNA-PEG mixtures, and, in particular, in the dispersed mesophases formed via polymer and salt induced (<em>psi</em>-) condensation. Being in complex with DNA, Hoechst 33258 shows a high sensitivity to the changes in osmotic conditions – the addition of PEG leads to a release of the dye molecules. However, this effect nonlinearly depends on osmolality. Individually, neither PEG nor NaCl at the studied concentrations significantly affect its complex with nucleic acid. The effect is caused precisely by their synergistic action. In cases of the dispersed systems formation, significant fraction of Hoechst 33258 molecules is retained within the resulting particles and is protected even from further increase in osmolality. This is partly due to competition between the processes of the dye releasing and formation of the dispersed particles.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"339 ","pages":"Article 126272"},"PeriodicalIF":4.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-18DOI: 10.1016/j.saa.2025.126266
Vincent Milano , Muhammad Riswan , Putri Dwi Jayanti , Nurul Imani Istiqomah , Zurnansyah , Nugraheni Puspita Rini , Karina Anggraeni , Nining Sumawati Asri , Julia Angel , Abhishek Sharma , Daoud Ali , Chotimah , Edi Suharyadi
In this study, a fast response, real time, accurate, and non destructive alcohol detection method using surface plasmon resonance (SPR) technique was purposed. The SPR measurement was performed using 5-layers Krestchmann configuration with a layer structure of prism/Au thin film/Fe3O4/rGO nanocomposite/alcohol compounds/air. The Fe3O4/rGO nanocomposite was successfully synthesized using the green route utilizing Moringa oleifera and Amaranthus viridis leaf extract. X-ray diffraction analysis showed the nanocomposite has a face-centered cubic with an inverse spinel structure with a crystallite size of 5.6–5.8 nm. The size of Fe3O4 NPs in the Fe3O4/rGO nanocomposite was variated from 10.6–13.0 nm and showed that there is no impurities in the sample. Fourier transform infra-red analysis also validates the existence of Fe3O4 and rGO indicated by the FeO and CC bond, respectively. The interaction between Fe3O4 and rGO can also be observed through the coordinational bonding FeOC, which is validated by the presence of FeO and CO bonds. The optical properties were studied using ultraviolet–visible spectroscopy, which shows an energy gap of 2.36 eV. Magnetic properties of Fe3O4/rGO nanocomposite show a superparamagnetic characteristic with the saturation magnetization of 40.53 emu/g, magnetic susceptibility of 3.62 10−2, and the domain size is 6.22 nm. The SPR angle shifts when applied with Fe3O4/rGO nanocomposite. The addition of alcohol compound further shifted the SPR angle by 0.22°, 0.61°, and 1.19° for methanol, ethanol, and IPA, respectively. This noticeable shift shows a possibility for early detection to differentiate these 3 compounds. The presence of a magnetic field further shifts the SPR angle by 0.08°, 0.08°, and 0.10° for 40, 60, and 80 Oe, which indicates an increase in sensitivity. Therefore, the combination of applied magnetic field and green synthesized Fe3O4/rGO nanocomposite as an eco-friendly interface layer are potential to enhance the sensitivity of SPR to detect the alcohol compounds.
{"title":"Highly sensitive surface plasmon resonance-based sensor using green synthesized Fe3O4/rGO interface layer utilizing plant leaf extracts for alcohol compound detection","authors":"Vincent Milano , Muhammad Riswan , Putri Dwi Jayanti , Nurul Imani Istiqomah , Zurnansyah , Nugraheni Puspita Rini , Karina Anggraeni , Nining Sumawati Asri , Julia Angel , Abhishek Sharma , Daoud Ali , Chotimah , Edi Suharyadi","doi":"10.1016/j.saa.2025.126266","DOIUrl":"10.1016/j.saa.2025.126266","url":null,"abstract":"<div><div>In this study, a fast response, real time, accurate, and non destructive alcohol detection method using surface plasmon resonance (SPR) technique was purposed. The SPR measurement was performed using 5-layers Krestchmann configuration with a layer structure of prism/Au thin film/Fe<sub>3</sub>O<sub>4</sub>/rGO nanocomposite/alcohol compounds/air. The Fe<sub>3</sub>O<sub>4</sub>/rGO nanocomposite was successfully synthesized using the green route utilizing <em>Moringa oleifera</em> and <em>Amaranthus viridis</em> leaf extract. X-ray diffraction analysis showed the nanocomposite has a face-centered cubic with an inverse spinel structure with a crystallite size of 5.6–5.8 nm. The size of Fe<sub>3</sub>O<sub>4</sub> NPs in the Fe<sub>3</sub>O<sub>4</sub>/rGO nanocomposite was variated from 10.6–13.0 nm and showed that there is no impurities in the sample. Fourier transform infra-red analysis also validates the existence of Fe<sub>3</sub>O<sub>4</sub> and rGO indicated by the Fe<img>O and C<img>C bond, respectively. The interaction between Fe<sub>3</sub>O<sub>4</sub> and rGO can also be observed through the coordinational bonding Fe<img>O<img>C, which is validated by the presence of Fe<img>O and C<img>O bonds. The optical properties were studied using ultraviolet–visible spectroscopy, which shows an energy gap of 2.36 eV. Magnetic properties of Fe<sub>3</sub>O<sub>4</sub>/rGO nanocomposite show a superparamagnetic characteristic with the saturation magnetization of 40.53 emu/g, magnetic susceptibility of 3.62 <span><math><mrow><mo>×</mo></mrow></math></span> 10<sup>−2</sup>, and the domain size is 6.22 nm. The SPR angle shifts when applied with Fe<sub>3</sub>O<sub>4</sub>/rGO nanocomposite. The addition of alcohol compound further shifted the SPR angle by 0.22°, 0.61°, and 1.19° for methanol, ethanol, and IPA, respectively. This noticeable shift shows a possibility for early detection to differentiate these 3 compounds. The presence of a magnetic field further shifts the SPR angle by 0.08°, 0.08°, and 0.10° for 40, 60, and 80 Oe, which indicates an increase in sensitivity. Therefore, the combination of applied magnetic field and green synthesized Fe<sub>3</sub>O<sub>4</sub>/rGO nanocomposite as an eco-friendly interface layer are potential to enhance the sensitivity of SPR to detect the alcohol compounds.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"339 ","pages":"Article 126266"},"PeriodicalIF":4.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-18DOI: 10.1016/j.saa.2025.126268
Anjana Sreekumar, C. Raksha, Ajil R. Nair, Akhil Sivan
This paper discusses the detailed sensing studies of a fluorene-based fluorophore for the sensitive and selective detection of fluoride ions in the solution state. The fluorophore FOPD has been synthesised from 9H-fluoren-9-one and o-phenylene diamine by simple reaction set-up, which was then structurally characterised by various spectroscopic techniques including FT-IR, NMR, and HRMS analyses. Further, the sensing potential of the fluorophore was carried out by UV–visible and fluorescence spectroscopic techniques. Various parameters including sensitivity, selectivity, interference, the influence of pH, and limit of detection were successfully validated experimentally, thereby confirming the excellent ability of FOPD in detecting fluoride ions. Computational studies, including Density Functional Theory (DFT), were employed to optimise the molecular structure of FOPD, explore its Frontier Molecular Orbitals (FMOs), and identify the plausible interaction between fluoride ions. Further, topological analyses such as ELF, LOL, RDG and QTAIM provide valuable insights into the non-bonding and intramolecular hydrogen bonding interactions, enabling a clearer understanding of the sensing mechanism. Finally, the toxicity analysis of FOPD revealed that it is relatively non-toxic with an excellent LOD of 0.125 µM, underscoring its potential as a safe and environmentally friendly fluorophore for the selective detection of fluoride ions.
{"title":"Advancing fluoride ion sensing with a fluorene-derived fluorophore: A comprehensive experimental and computational study","authors":"Anjana Sreekumar, C. Raksha, Ajil R. Nair, Akhil Sivan","doi":"10.1016/j.saa.2025.126268","DOIUrl":"10.1016/j.saa.2025.126268","url":null,"abstract":"<div><div>This paper discusses the detailed sensing studies of a fluorene-based fluorophore for the sensitive and selective detection of fluoride ions in the solution state. The fluorophore <strong>FOPD</strong> has been synthesised from 9<em>H</em>-fluoren-9-one and <em>o</em>-phenylene diamine by simple reaction set-up, which was then structurally characterised by various spectroscopic techniques including FT-IR, NMR, and HRMS analyses. Further, the sensing potential of the fluorophore was carried out by UV–visible and fluorescence spectroscopic techniques. Various parameters including sensitivity, selectivity, interference, the influence of pH, and limit of detection were successfully validated experimentally, thereby confirming the excellent ability of <strong>FOPD</strong> in detecting fluoride ions. Computational studies, including Density Functional Theory (DFT), were employed to optimise the molecular structure of <strong>FOPD</strong>, explore its Frontier Molecular Orbitals (FMOs), and identify the plausible interaction between fluoride ions. Further, topological analyses such as ELF, LOL, RDG and QTAIM provide valuable insights into the non-bonding and intramolecular hydrogen bonding interactions, enabling a clearer understanding of the sensing mechanism. Finally, the toxicity analysis of <strong>FOPD</strong> revealed that it is relatively non-toxic with an excellent LOD of 0.125 µM, underscoring its potential as a safe and environmentally friendly fluorophore for the selective detection of fluoride ions.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"339 ","pages":"Article 126268"},"PeriodicalIF":4.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-17DOI: 10.1016/j.saa.2025.126262
Tian-Zhen Liu , Xiao-Hui Chi , Bing-Yu Wei , Jun-Ying Miao , Bao-Xiang Zhao , Zhao-Min Lin
Inter-organellar interactions play indispensable roles in regulating cellular homeostasis, necessitating advanced methodologies for their simultaneous and discriminative visualization. Fluorescent probes, prized for their sensitivity and spatiotemporal resolution, are pivotal tools for elucidating organelle dynamics in live-cell studies. However, current technologies remain limited in achieving robust dual-color imaging of multiple organelles with minimal crosstalk. To address this gap, we developed a Förster resonance energy transfer (FRET)-based ratiometric probe leveraging the pH-responsive spiro-pyran motif, which undergoes reversible ring-opening/closing transitions. This probe enables concurrent dual-color visualization of lipid droplets (LDs) and the endoplasmic reticulum (ER) in HeLa cells under single-excitation conditions, achieving high Pearson’s correlation coefficients and minimal spectral overlap. Our work advances the design of multifunctional probes for decoding inter-organelle communication in live systems.
{"title":"A novel FRET-based fluorescent probe capable of simultaneously imaging lipid droplets and the endoplasmic reticulum with two distinct fluorescence signals in HeLa cells","authors":"Tian-Zhen Liu , Xiao-Hui Chi , Bing-Yu Wei , Jun-Ying Miao , Bao-Xiang Zhao , Zhao-Min Lin","doi":"10.1016/j.saa.2025.126262","DOIUrl":"10.1016/j.saa.2025.126262","url":null,"abstract":"<div><div>Inter-organellar interactions play indispensable roles in regulating cellular homeostasis, necessitating advanced methodologies for their simultaneous and discriminative visualization. Fluorescent probes, prized for their sensitivity and spatiotemporal resolution, are pivotal tools for elucidating organelle dynamics in live-cell studies. However, current technologies remain limited in achieving robust dual-color imaging of multiple organelles with minimal crosstalk. To address this gap, we developed a Förster resonance energy transfer (FRET)-based ratiometric probe leveraging the pH-responsive spiro-pyran motif, which undergoes reversible ring-opening/closing transitions. This probe enables concurrent dual-color visualization of lipid droplets (LDs) and the endoplasmic reticulum (ER) in HeLa cells under single-excitation conditions, achieving high Pearson’s correlation coefficients and minimal spectral overlap. Our work advances the design of multifunctional probes for decoding inter-organelle communication in live systems.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"339 ","pages":"Article 126262"},"PeriodicalIF":4.3,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-17DOI: 10.1016/j.saa.2025.126257
Badriah Saad Al-Farhan , Ahmed Abdulhafez Hamad
A novel application of a spectrofluorimetric method has been developed and validated for the stability analysis and quantification of midodrine hydrochloride in tablets and crude form. This study describes a technique based on the selective derivatization of midodrine’s (MDN) primary amine group with NBD-Cl reagent under a borate buffer system (pH 8.5), yielding a highly fluorescent benzofurazan derivative. The product was measured at λex = 462 nm and λem = 537 nm, demonstrating a linear range of 30–600 ng/mL (r = 0.9998). The method’s detection (8.9 ng/mL) and quantitation (26.98 ng/mL) limits were determined. Validation followed ICH guidelines, confirming precision, accuracy (recovery: 98.9–100.7 %), and absence of excipient interference in commercial formulations (tablets and oral drops). The method was applied to assess stress-induced degradation (acid, alkali, oxidation, aqueous, and photolytic conditions) and determine degradation kinetics under each condition. Additionally, content uniformity analysis of tablets was performed per USP guidelines, demonstrating robustness for quality control applications.
{"title":"The first spectrofluorimetric-based approach for studying stability-indicating assay and quantifying midodrine in its bulk powder, prescribed matrices; application to content homogeneity testing and sustainability evaluation","authors":"Badriah Saad Al-Farhan , Ahmed Abdulhafez Hamad","doi":"10.1016/j.saa.2025.126257","DOIUrl":"10.1016/j.saa.2025.126257","url":null,"abstract":"<div><div>A novel application of a spectrofluorimetric method has been developed and validated for the stability analysis and quantification of midodrine hydrochloride in tablets and crude form. This study describes a technique based on the selective derivatization of midodrine’s (MDN) primary amine group with NBD-Cl reagent under a borate buffer system (pH 8.5), yielding a highly fluorescent benzofurazan derivative. The product was measured at λ<sub>ex</sub> = 462 nm and λ<sub>em</sub> = 537 nm, demonstrating a linear range of 30–600 ng/mL (r = 0.9998). The method’s detection (8.9 ng/mL) and quantitation (26.98 ng/mL) limits were determined. Validation followed ICH guidelines, confirming precision, accuracy (recovery: 98.9–100.7 %), and absence of excipient interference in commercial formulations (tablets and oral drops). The method was applied to assess stress-induced degradation (acid, alkali, oxidation, aqueous, and photolytic conditions) and determine degradation kinetics under each condition. Additionally, content uniformity analysis of tablets was performed per USP guidelines, demonstrating robustness for quality control applications.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"339 ","pages":"Article 126257"},"PeriodicalIF":4.3,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-17DOI: 10.1016/j.saa.2025.126242
He Gao , Xianjing Zhang , Haiyan Ma , Yuyao Li , Dongyuan Xu , Longbin Xu
Sulfur dioxide (SO2) is a significant atmospheric pollutant and food additive, with excessive sulfite (HSO3−) consumption linked to health risks such as respiratory and cardiovascular disorders. Reliable, sensitive detection of HSO3− is essential for food safety and environmental monitoring. Here, we present a novel fluorescent probe (HMQ) for the selective detection of HSO3− in biological and environmental samples. The probe exhibits a distinct “ON-OFF” fluorescence response due to a nucleophilic addition mechanism, enabling high selectivity for HSO3− over other anions. HMQ was successfully applied for detecting exogenous HSO3− in living cells and for monitoring sulfite contamination in food samples. Additionally, test strips impregnated with HMQ provide a simple and rapid method for detecting HSO3− (SO2) in aqueous solutions and gaseous environments. The probe demonstrates excellent sensitivity, with linear fluorescence responses and high recovery rates in both food and serum samples. This work provides a versatile tool for sulfite detection, with potential applications in food safety, environmental monitoring, and disease research.
{"title":"Development of a selective fluorescent probe for sensitive detection of HSO3− in biological and environmental samples","authors":"He Gao , Xianjing Zhang , Haiyan Ma , Yuyao Li , Dongyuan Xu , Longbin Xu","doi":"10.1016/j.saa.2025.126242","DOIUrl":"10.1016/j.saa.2025.126242","url":null,"abstract":"<div><div>Sulfur dioxide (SO<sub>2</sub>) is a significant atmospheric pollutant and food additive, with excessive sulfite (HSO<sub>3</sub><sup>−</sup>) consumption linked to health risks such as respiratory and cardiovascular disorders. Reliable, sensitive detection of HSO<sub>3</sub><sup>−</sup> is essential for food safety and environmental monitoring. Here, we present a novel fluorescent probe (HMQ) for the selective detection of HSO<sub>3</sub><sup>−</sup> in biological and environmental samples. The probe exhibits a distinct “ON-OFF” fluorescence response due to a nucleophilic addition mechanism, enabling high selectivity for HSO<sub>3</sub><sup>−</sup> over other anions. HMQ was successfully applied for detecting exogenous HSO<sub>3</sub><sup>−</sup> in living cells and for monitoring sulfite contamination in food samples. Additionally, test strips impregnated with HMQ provide a simple and rapid method for detecting HSO<sub>3</sub><sup>−</sup> (SO<sub>2</sub>) in aqueous solutions and gaseous environments. The probe demonstrates excellent sensitivity, with linear fluorescence responses and high recovery rates in both food and serum samples. This work provides a versatile tool for sulfite detection, with potential applications in food safety, environmental monitoring, and disease research.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"339 ","pages":"Article 126242"},"PeriodicalIF":4.3,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-17DOI: 10.1016/j.saa.2025.126258
Dan Vrtiška, Miloš Auersvald, Zlata Mužíková, Pavel Šimáček
A prediction model based on the processing of FTIR spectra and partial least squares regression (PLS) was developed for the determination of the hydroperoxide number of diesel fuels. The sets of calibration and validation standards were composed of fresh and aged diesel fuels. The hydroperoxide number determined via the standard titration method ranged from 0 to 65 mg·kg−1. While the calibration standards were utilized for the model construction, the validation standards were used for its optimization and validation. Several preprocessing methods, together with various numbers of latent variables, were utilized to improve model prediction ability. The model with the lowest Root Mean Square Error of Prediction was developed using mean centering, variance scaling, second derivative, and smoothing methods. Both examined smoothing techniques, i.e., Savitzky-Golay and Gap-Segment derivative, provided similar results. The use of the commonly available and affordable FTIR method, allowing rapid analysis, proved to be cost effective alternative to highly erroneous and laborious titration methods utilizing toxic reagents. In general, the developed model showed good predictive ability and is a perfect solution for fast screening of oxidative aging level of conventional hydrocarbon-based fuels.
{"title":"Prediction of hydroperoxide number of diesel fuel using FTIR and chemometrics","authors":"Dan Vrtiška, Miloš Auersvald, Zlata Mužíková, Pavel Šimáček","doi":"10.1016/j.saa.2025.126258","DOIUrl":"10.1016/j.saa.2025.126258","url":null,"abstract":"<div><div>A prediction model based on the processing of FTIR spectra and partial least squares regression (PLS) was developed for the determination of the<!--> <!-->hydroperoxide number of diesel fuels. The sets of calibration and validation standards were composed of fresh and aged diesel fuels. The hydroperoxide number determined via the standard titration method ranged from 0 to 65 mg·kg<sup>−1</sup>. While the calibration standards were utilized for the model construction, the validation standards were used for its optimization and validation. Several preprocessing methods, together with various numbers of latent variables, were utilized to improve model prediction ability. The model with the lowest Root Mean Square Error of Prediction was developed using mean centering, variance scaling, second derivative, and smoothing methods. Both examined smoothing techniques, i.e., Savitzky-Golay and Gap-Segment derivative, provided similar results. The use of the commonly available and affordable FTIR method, allowing rapid analysis, proved to be cost effective alternative to highly erroneous and laborious titration methods utilizing toxic reagents. In general, the developed model showed good predictive ability and is a perfect solution for fast screening of oxidative aging level of conventional hydrocarbon-based fuels.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"339 ","pages":"Article 126258"},"PeriodicalIF":4.3,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-17DOI: 10.1016/j.saa.2025.126219
Longjun Xiong, Yu Liu, Yutian Jiao, Gongli Wei, Baocai Xu, Fu Han, Li Zhao
A fluorescence detection platform for α-amylase was developed by exploiting the host–guest inclusion complex formed between γ-cyclodextrin (γ-CD) and a pyrene-functionalized amphiphile (P10CG). Spectroscopic analysis revealed that the pyrene moiety was encapsulated within the γ-CD cavity in a 2:2 stoichiometric ratio, inducing characteristic excimer fluorescence. Upon enzymatic hydrolysis of γ-CD by α-amylase, the subsequent release of P10CG led to a marked decrease in excimer emission intensity. A quantitative linear relationship (R2 > 0.99) was observed between the monomer-to-excimer intensity ratio and α-amylase concentrations ranging from 1 to 5 U/mL, with a calculated detection limit of 0.135 U/mL (S/N = 3). The γ-CD/P10CG supramolecular system demonstrated satisfactory sensitivity and selectivity for α-amylase in both buffer solutions and diluted serum matrices, thus providing a potential sensing system for α-amylase in complex biological systems.
{"title":"Fluorescence detection of α-amylase based on a host–guest complex between a pyrene-derived amphiphile and γ-cyclodextrin","authors":"Longjun Xiong, Yu Liu, Yutian Jiao, Gongli Wei, Baocai Xu, Fu Han, Li Zhao","doi":"10.1016/j.saa.2025.126219","DOIUrl":"10.1016/j.saa.2025.126219","url":null,"abstract":"<div><div>A fluorescence detection platform for α-amylase was developed by exploiting the host–guest inclusion complex formed between γ-cyclodextrin (γ-CD) and a pyrene-functionalized amphiphile (P10CG). Spectroscopic analysis revealed that the pyrene moiety was encapsulated within the γ-CD cavity in a 2:2 stoichiometric ratio, inducing characteristic excimer fluorescence. Upon enzymatic hydrolysis of γ-CD by α-amylase, the subsequent release of P10CG led to a marked decrease in excimer emission intensity. A quantitative linear relationship (R<sup>2</sup> > 0.99) was observed between the monomer-to-excimer intensity ratio and α-amylase concentrations ranging from 1 to 5 U/mL, with a calculated detection limit of 0.135 U/mL (S/N = 3). The γ-CD/P10CG supramolecular system demonstrated satisfactory sensitivity and selectivity for α-amylase in both buffer solutions and diluted serum matrices, thus providing a potential sensing system for α-amylase in complex biological systems.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"339 ","pages":"Article 126219"},"PeriodicalIF":4.3,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-17DOI: 10.1016/j.saa.2025.126259
Wei Gao , Hao Hu , Jinkun Xue , Yongrun Dong , Wen Li , Xia Zhao , Xiang Mao , Zequan Li
Carbon dots (CDs) have attracted considerable interest as fluorescent nanomaterials; however, their long-afterglow emission properties remain underexplored. In this study, we synthesized dual-mode afterglow CDs exhibiting room-temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) via fluorine-sodium (F, Na) co-doping, achieving an extended afterglow lifetime of 574 ms. Under 365 nm UV excitation, the afterglow emission persists for 14 s (naked-eye observation) and 40 s (instrumentally quantified), demonstrating exceptional temporal resolution. Na doping enhances afterglow intensity by 11.3 %, while fluorine doping reduces the singlet–triplet energy gap (ΔEST) to 0.036 eV, facilitating efficient Reverse Intersystem Crossing and enabling TADF behavior. These synergistic effects position the developed CDs as promising candidates for anti-counterfeiting systems, multilevel data encryption, and high-security optical tagging.
{"title":"F and Na Co-doped carbon dots with enhanced afterglow emission for applications in fingerprint recognition and information encryption","authors":"Wei Gao , Hao Hu , Jinkun Xue , Yongrun Dong , Wen Li , Xia Zhao , Xiang Mao , Zequan Li","doi":"10.1016/j.saa.2025.126259","DOIUrl":"10.1016/j.saa.2025.126259","url":null,"abstract":"<div><div>Carbon dots (CDs) have attracted considerable interest as fluorescent nanomaterials; however, their long-afterglow emission properties remain underexplored. In this study, we synthesized dual-mode afterglow CDs exhibiting room-temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) via fluorine-sodium (F, Na) co-doping, achieving an extended afterglow lifetime of 574 ms. Under 365 nm UV excitation, the afterglow emission persists for 14 s (naked-eye observation) and 40 s (instrumentally quantified), demonstrating exceptional temporal resolution. Na doping enhances afterglow intensity by 11.3 %, while fluorine doping reduces the singlet–triplet energy gap (ΔE<sub>ST</sub>) to 0.036 eV, facilitating efficient Reverse Intersystem Crossing and enabling TADF behavior. These synergistic effects position the developed CDs as promising candidates for anti-counterfeiting systems, multilevel data encryption, and high-security optical tagging.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"339 ","pages":"Article 126259"},"PeriodicalIF":4.3,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-17DOI: 10.1016/j.saa.2025.126183
Qixin Zhao , Jiao Wu , Jiale Yao , Zengjin Liu , Changqiang Li , Qin Sun
Triple-negative breast cancer (TNBC) is a cancerous tumor that poses a global threat to women’s lives and health. Currently, chemotherapy is the preferred treatment for advanced TNBC. In this work, we have identified a novel NIR fluorescent inhibitor, SWMU690, which can effectively inhibit the proliferation of TNBC at low doses. The half-maximal inhibitory concentration (IC50) values of SWMU690 against the MDA-MB-231, 4 T1, and T47D cell lines were determined to be 104 nM, 509.4 nM, and 206 nM, respectively. We found that SWMU690 specifically localized in mitochondria to trigger mitochondria-mediated intrinsic apoptotic pathways. Furthermore, SWMU690 can suppress the production of ATP to inhibit TNBC metastasis. This study demonstrated the advantage of disrupting the function of mitochondria in inhibiting the proliferation and metastasis of TNBC, and may have other applications in the treatment of other malignant tumors.
{"title":"Simultaneously induce apoptosis and inhibiting metastasis of Triple negative breast cancer Enabled by a highly potent NIR fluorescent inhibitor","authors":"Qixin Zhao , Jiao Wu , Jiale Yao , Zengjin Liu , Changqiang Li , Qin Sun","doi":"10.1016/j.saa.2025.126183","DOIUrl":"10.1016/j.saa.2025.126183","url":null,"abstract":"<div><div>Triple-negative breast cancer (TNBC) is a cancerous tumor that poses a global threat to women’s lives and health. Currently, chemotherapy is the preferred treatment for advanced TNBC. In this work, we have identified a novel NIR fluorescent inhibitor, SWMU690, which can effectively inhibit the proliferation of TNBC at low doses. The half-maximal inhibitory concentration (IC<sub>50</sub>) values of SWMU690 against the MDA-MB-231, 4 T1, and T47D cell lines were determined to be 104 nM, 509.4 nM, and 206 nM, respectively. We found that SWMU690 specifically localized in mitochondria to trigger mitochondria-mediated intrinsic apoptotic pathways. Furthermore, SWMU690 can suppress the production of ATP to inhibit TNBC metastasis. This study demonstrated the advantage of disrupting the function of mitochondria in inhibiting the proliferation and metastasis of TNBC, and may have other applications in the treatment of other malignant tumors.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"339 ","pages":"Article 126183"},"PeriodicalIF":4.3,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}