We present Raman study of the L-lactide/ε-caprolactone (PLCL) copolymers with the L-lactide (LLA) content from 10 to 90 mol %. The copolymers were synthesized by bulk ring-opening polymerization. As additional method, we used the wide-angle X-ray scattering analysis to obtain the crystallinity degree of the poly(L-lactide) (PLLA) and poly(ε-caprolactone) (PCL) blocks. We extend the previously proposed method of determination of the crystallinity degree of PLLA areas in the PLCL copolymers up to the ε-caprolactone (CL) content of 50 mol %. The method includes analysis of the ratio of the peak intensities of the PLLA bands at 411 and 874 cm−1. We also suggest for the first time using the PCL bands at 958 and 1110 cm−1 to evaluate the crystallinity degree of PCL blocks in the PLCL copolymers. Besides, we extend the previously proposed method of evaluation of the relative contents of the comonomers in the PLCL copolymers to the whole range of the CL content as well as to analysis of melt-mixed PLLA/PCL blend. The method is based on the measurement of the ratio of the peak intensities of the PLLA band at 2947 cm−1 and the PCL band at 2914 cm−1.
{"title":"Raman structural analysis of L-lactide/ε-caprolactone copolymers and poly(L-lactide)/poly(ε-caprolactone) blends","authors":"S.O. Liubimovskii , V.S. Novikov , E.V. Anokhin , S.M. Kuznetsov , A.V. Bakirov , V.A. Demina , N.G. Sedush , S.N. Chvalun , M.N. Moskovskiy , S.V. Gudkov , G. Yu. Nikolaeva","doi":"10.1016/j.saa.2025.126018","DOIUrl":"10.1016/j.saa.2025.126018","url":null,"abstract":"<div><div>We present Raman study of the L-lactide/ε-caprolactone (PLCL) copolymers with the L-lactide (LLA) content from 10 to 90 mol %. The copolymers were synthesized by bulk ring-opening polymerization. As additional method, we used the wide-angle X-ray scattering analysis to obtain the crystallinity degree of the poly(L-lactide) (PLLA) and poly(ε-caprolactone) (PCL) blocks. We extend the previously proposed method of determination of the crystallinity degree of PLLA areas in the PLCL copolymers up to the ε-caprolactone (CL) content of 50 mol %. The method includes analysis of the ratio of the peak intensities of the PLLA bands at 411 and 874 cm<sup>−1</sup>. We also suggest for the first time using the PCL bands at 958 and 1110 cm<sup>−1</sup> to evaluate the crystallinity degree of PCL blocks in the PLCL copolymers. Besides, we extend the previously proposed method of evaluation of the relative contents of the comonomers in the PLCL copolymers to the whole range of the CL content as well as to analysis of melt-mixed PLLA/PCL blend. The method is based on the measurement of the ratio of the peak intensities of the PLLA band at 2947 cm<sup>−1</sup> and the PCL band at 2914 cm<sup>−1</sup>.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"336 ","pages":"Article 126018"},"PeriodicalIF":4.3,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642336","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 : 2025-03-06DOI: 10.1016/j.saa.2025.126000
Farooq M. Almutairi , Yusuf S. Althobaiti , Maram H. Abduljabbar , Rami M. Alzhrani , Reem M. Alnemari , Muneef M. Aldhafeeri , Ahmed Serag , Atiah H. Almalki
In this study, a novel analytical method was developed for the determination of bupropion in pharmaceutical formulations and spiked plasma samples using N, S co-doped carbon quantum dots (N,S CQDs) as a fluorescent probe. The N,S CQDs were thoroughly characterized and its optical properties were investigated. The developed N,S CQDs exhibited blue emission at 435 nm upon excitation at 357 nm. Detailed studies on the sensing mechanism revealed that the fluorescence quenching of the N,S CQDs by bupropion follows a static quenching mechanism, as confirmed by Stern-Volmer analysis and thermodynamic parameters. The quenching parameters were further optimized using a central composite experimental design, and the method was validated according to ICH guidelines. The method displayed excellent linearity in the range of 0.05–1.5 μg/mL, with a limit of detection of 0.016 μg/mL. The developed method was successfully applied for the analysis of bupropion in pharmaceutical formulations and spiked human plasma samples, with satisfactory recoveries. Moreover, statistical analysis revealed no significant differences between the results obtained using the proposed method and a reference HPLC method, indicating the reliability of the developed approach. Greenness and blueness of the method was evaluated using the AGREE and BAGI tools respectively, demonstrating the environmentally friendly and analytical practicality of the proposed technique.
{"title":"Spectrofluorimetric determination of bupropion using N,S co-doped carbon quantum dots: Mechanistic investigation, response surface optimization, and application to pharmaceutical formulations, spiked plasma and environmental samples","authors":"Farooq M. Almutairi , Yusuf S. Althobaiti , Maram H. Abduljabbar , Rami M. Alzhrani , Reem M. Alnemari , Muneef M. Aldhafeeri , Ahmed Serag , Atiah H. Almalki","doi":"10.1016/j.saa.2025.126000","DOIUrl":"10.1016/j.saa.2025.126000","url":null,"abstract":"<div><div>In this study, a novel analytical method was developed for the determination of bupropion in pharmaceutical formulations and spiked plasma samples using N, S co-doped carbon quantum dots (N,S CQDs) as a fluorescent probe. The N,S CQDs were thoroughly characterized and its optical properties were investigated. The developed N,S CQDs exhibited blue emission at 435 nm upon excitation at 357 nm. Detailed studies on the sensing mechanism revealed that the fluorescence quenching of the N,S CQDs by bupropion follows a static quenching mechanism, as confirmed by Stern-Volmer analysis and thermodynamic parameters. The quenching parameters were further optimized using a central composite experimental design, and the method was validated according to ICH guidelines. The method displayed excellent linearity in the range of 0.05–1.5 μg/mL, with a limit of detection of 0.016 μg/mL. The developed method was successfully applied for the analysis of bupropion in pharmaceutical formulations and spiked human plasma samples, with satisfactory recoveries. Moreover, statistical analysis revealed no significant differences between the results obtained using the proposed method and a reference HPLC method, indicating the reliability of the developed approach. Greenness and blueness of the method was evaluated using the AGREE and BAGI tools respectively, demonstrating the environmentally friendly and analytical practicality of the proposed technique.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"335 ","pages":"Article 126000"},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593123","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}
Furocoumarins are photo-active arising in several medicinal plants when they are subjected to stress devising varied medicinal applications. Angelicin and psoralen are the two main active components of Psoralea corylifolia L., an herbal-medicinal plant used from early times to treat numerous skin-related disorders. It is extensively dispersed in the therapeutics in Indian and Chinese herbal mode treatment. Here we synthesized two isomeric furocoumarins angelicin and psoralen and investigated their interaction with a cysteine protease proteolytic enzyme bromelain, using different spectroscopic techniques like steady state fluorescence and circular dichroism to understand the binding affinity of the two furocoumarins with bromelain. Bromelain is a well-known phytotherapeutic ingredient displaying widespread medicinal applications. The binding constants and the number of binding sites for the interactions of angelicin and psoralen with bromelain were evaluated using the steady state fluorescence data at 298 K. An in-silico investigation was executed by docking the two isomeric furocoumarins angelicin and psoralen with bromelain which revealed that both bind with the same energy but at different sites, which also alters a little more in the case of psoralen than angelicin the secondary structure of bromelain as evidenced in Circular dichroism spectra. DFT study revealed the stability of both moieties. In conclusion, this study shed light on the effective application of bromelain complexed with angelicin and psoralen, for developing functional foods and also can be considered an effective carrier for angelicin and psoralen.
{"title":"A comparison of binding interaction of angelicin and psoralen to bromelain a cysteine protease: Steady-state fluorescence, circular dichroism and molecular docking study","authors":"Sourav Pakrashy , Prakash K. Mandal , Sandip Paul , Sourav Misra , Jishu Mandal , Malay Dolai , Anjoy Majhi","doi":"10.1016/j.saa.2025.125964","DOIUrl":"10.1016/j.saa.2025.125964","url":null,"abstract":"<div><div>Furocoumarins are photo-active arising in several medicinal plants when they are subjected to stress devising varied medicinal applications. Angelicin and psoralen are the two main active components of <em>Psoralea corylifolia L.</em>, an herbal-medicinal plant used from early times to treat numerous skin-related disorders. It is extensively dispersed in the therapeutics in Indian and Chinese herbal mode treatment. Here we synthesized two isomeric furocoumarins angelicin and psoralen and investigated their interaction with a cysteine protease proteolytic enzyme bromelain, using different spectroscopic techniques like steady state fluorescence and circular dichroism to understand the binding affinity of the two furocoumarins with bromelain. Bromelain is a well-known phytotherapeutic ingredient displaying widespread medicinal applications. The binding constants and the number of binding sites for the interactions of angelicin and psoralen with bromelain were evaluated using the steady state fluorescence data at 298 K. An in-silico investigation was executed by docking the two isomeric furocoumarins angelicin and psoralen with bromelain which revealed that both bind with the same energy but at different sites, which also alters a little more in the case of psoralen than angelicin the secondary structure of bromelain as evidenced in Circular dichroism spectra. DFT study revealed the stability of both moieties. In conclusion, this study shed light on the effective application of bromelain complexed with angelicin and psoralen, for developing functional foods and also can be considered an effective carrier for angelicin and psoralen.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"336 ","pages":"Article 125964"},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629424","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 : 2025-03-06DOI: 10.1016/j.saa.2025.125997
Han Xu, Ruichan Lv
Lung cancer is a malignant tumor that poses a serious threat to human health. Existing lung cancer diagnostic techniques face the challenges of high cost and slow diagnosis. Early and rapid diagnosis and treatment are essential to improve the outcome of lung cancer. In this study, a deep learning-based multi-modal spectral information fusion (MSIF) network is proposed for lung adenocarcinoma cell detection. First, multi-modal data of Fourier transform infrared spectra, UV–vis absorbance spectra, and fluorescence spectra of normal and patient cells were collected. Subsequently, the spectral text data were efficiently processed by one-dimensional convolutional neural network. The global and local features of the spectral images are deeply mined by the hybrid model of ResNet and Transformer. An adaptive depth-wise convolution (ADConv) is introduced to be applied to feature extraction, overcoming the shortcomings of conventional convolution. In order to achieve feature learning between multi-modalities, a cross-modal interaction fusion (CMIF) module is designed. This module fuses the extracted spectral image and text features in a multi-faceted interaction, enabling full utilization of multi-modal features through feature sharing. The method demonstrated excellent performance on the test sets of Fourier transform infrared spectra, UV–vis absorbance spectra and fluorescence spectra, achieving 95.83 %, 97.92 % and 100 % accuracy, respectively. In addition, experiments validate the superiority of multi-modal spectral data and the robustness of the model generalization capability. This study not only provides strong technical support for the early diagnosis of lung cancer, but also opens a new chapter for the application of multi-modal data fusion in spectroscopy.
{"title":"Rapid diagnosis of lung cancer by multi-modal spectral data combined with deep learning","authors":"Han Xu, Ruichan Lv","doi":"10.1016/j.saa.2025.125997","DOIUrl":"10.1016/j.saa.2025.125997","url":null,"abstract":"<div><div>Lung cancer is a malignant tumor that poses a serious threat to human health. Existing lung cancer diagnostic techniques face the challenges of high cost and slow diagnosis. Early and rapid diagnosis and treatment are essential to improve the outcome of lung cancer. In this study, a deep learning-based multi-modal spectral information fusion (MSIF) network is proposed for lung adenocarcinoma cell detection. First, multi-modal data of Fourier transform infrared spectra, UV–vis absorbance spectra, and fluorescence spectra of normal and patient cells were collected. Subsequently, the spectral text data were efficiently processed by one-dimensional convolutional neural network. The global and local features of the spectral images are deeply mined by the hybrid model of ResNet and Transformer. An adaptive depth-wise convolution (ADConv) is introduced to be applied to feature extraction, overcoming the shortcomings of conventional convolution. In order to achieve feature learning between multi-modalities, a cross-modal interaction fusion (CMIF) module is designed. This module fuses the extracted spectral image and text features in a multi-faceted interaction, enabling full utilization of multi-modal features through feature sharing. The method demonstrated excellent performance on the test sets of Fourier transform infrared spectra, UV–vis absorbance spectra and fluorescence spectra, achieving 95.83 %, 97.92 % and 100 % accuracy, respectively. In addition, experiments validate the superiority of multi-modal spectral data and the robustness of the model generalization capability. This study not only provides strong technical support for the early diagnosis of lung cancer, but also opens a new chapter for the application of multi-modal data fusion in spectroscopy.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"335 ","pages":"Article 125997"},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593122","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 : 2025-03-05DOI: 10.1016/j.saa.2025.125989
Xingmei Xue , Xiaohui Tang , Chunrui Hu , Junjie Sun , Xiao Li , Sen Yang , Sarp Kerman , Sijia Xie , Xiumei Xu , Ran Ji , Chang Chen
Nanoimprint lithography (NIL) is gradually becoming a powerful tool for the fabrication of periodic nanostructures. This method can offer a more cost-effective solution for large-scale manufacturing compared to methods that only rely on deep ultraviolet (DUV) immersion, since the product of DUV immersion can be utilized as a Si mold to fabricate a reusable plastic stamp mold. In this work, arrays of plastic nanopillars coated with nanostructured gold film exhibiting ultra density prepared through NIL and Au sputtering are successfully developed. The obtained plastic nanopillar substrate is templated from Si nanopillar substrate with a pitch of 90 nm. As a result, the plastic nanopillar features a similar pitch size. Besides, benzenedithiol (BDT) was used as the standard analyte to evaluate the uniformity of the substrates as well as the SERS enhancement effect. Eventually, it is demonstrated that the substrate constituted of Au-capped plastic nanopillar shows a low coefficient of variation (CV) at 5.46 % along with a strong SERS enhancement effect. These performances match with the Si based SERS substrate manufactured via DUV immersion reported in our previous work.
{"title":"High-uniformity, low-cost, ultra-dense arrays of Au-capped plastic nanopillars fabricated via nanoimprint lithography as reliable SERS substrates","authors":"Xingmei Xue , Xiaohui Tang , Chunrui Hu , Junjie Sun , Xiao Li , Sen Yang , Sarp Kerman , Sijia Xie , Xiumei Xu , Ran Ji , Chang Chen","doi":"10.1016/j.saa.2025.125989","DOIUrl":"10.1016/j.saa.2025.125989","url":null,"abstract":"<div><div>Nanoimprint lithography (NIL) is gradually becoming a powerful tool for the fabrication of periodic nanostructures. This method can offer a more cost-effective solution for large-scale manufacturing compared to methods that only rely on deep ultraviolet (DUV) immersion, since the product of DUV immersion can be utilized as a Si mold to fabricate a reusable plastic stamp mold. In this work, arrays of plastic nanopillars coated with nanostructured gold film exhibiting ultra density prepared through NIL and Au sputtering are successfully developed. The obtained plastic nanopillar substrate is templated from Si nanopillar substrate with a pitch of 90 nm. As a result, the plastic nanopillar features a similar pitch size. Besides, benzenedithiol (BDT) was used as the standard analyte to evaluate the uniformity of the substrates as well as the SERS enhancement effect. Eventually, it is demonstrated that the substrate constituted of Au-capped plastic nanopillar shows a low coefficient of variation (CV) at 5.46 % along with a strong SERS enhancement effect. These performances match with the Si based SERS substrate manufactured via DUV immersion reported in our previous work.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"335 ","pages":"Article 125989"},"PeriodicalIF":4.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580001","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 : 2025-03-05DOI: 10.1016/j.saa.2025.126001
Ya-Tong Liu , Qian-Qian Zhang , Si-Yi Yao , Zhi-Bo Jiang , Hao Wang , Yue-Li Zou , Li-Xia Zhao
Given the profound implications of Al3+ and Zn2+ in the ecosystem and organism, there is a compelling demand for a robust method to simultaneously detect these ions. The novel near-infrared (NIR) fluorescent probe DDLH based on isophorone, offers efficient in vivo monitoring capabilities for Al3+/Zn2+. Simultaneously, DDLH displayed excellent selectivity, anti-interference, a low detection limit and rapidity responsiveness to Al3+/Zn2+, coupled with a high fluorescence quantum yield and substantial Stokes shift (220 nm). The binding mechanisms of DDLH to Al3+ (ESIPT effect)/Zn2+ (ICT effect) were unambiguously established through a series of comprehensive analytical techniques. Furthermore, the probe DDLH was also applied for bioimaging in Hela cells. Critically, DDLH exhibited remarkable performance in detecting Al3+ and Zn2+ in zebrafish. Therefore, the study demonstrated enormous potential in environmental monitoring and ecosystems, showing broad application prospects in living organisms.
{"title":"Unique isophorone-based NIR fluorescent probe with a high fluorescence quantum yield and larger stokes shift for Al3+ and Zn2+ level simultaneous monitoring in biological system","authors":"Ya-Tong Liu , Qian-Qian Zhang , Si-Yi Yao , Zhi-Bo Jiang , Hao Wang , Yue-Li Zou , Li-Xia Zhao","doi":"10.1016/j.saa.2025.126001","DOIUrl":"10.1016/j.saa.2025.126001","url":null,"abstract":"<div><div>Given the profound implications of Al<sup>3+</sup> and Zn<sup>2+</sup> in the ecosystem and organism, there is a compelling demand for a robust method to simultaneously detect these ions. The novel near-infrared (NIR) fluorescent probe <strong>DDLH</strong> based on isophorone, offers efficient in vivo monitoring capabilities for Al<sup>3+</sup>/Zn<sup>2+</sup>. Simultaneously, <strong>DDLH</strong> displayed excellent selectivity, anti-interference, a low detection limit and rapidity responsiveness to Al<sup>3+</sup>/Zn<sup>2+</sup>, coupled with a high fluorescence quantum yield and substantial Stokes shift (220 nm). The binding mechanisms of <strong>DDLH</strong> to Al<sup>3+</sup> (ESIPT effect)/Zn<sup>2+</sup> (ICT effect) were unambiguously established through a series of comprehensive analytical techniques. Furthermore, the probe <strong>DDLH</strong> was also applied for bioimaging in Hela cells. Critically, <strong>DDLH</strong> exhibited remarkable performance in detecting Al<sup>3+</sup> and Zn<sup>2+</sup> in zebrafish. Therefore, the study demonstrated enormous potential in environmental monitoring and ecosystems, showing broad application prospects in living organisms.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"335 ","pages":"Article 126001"},"PeriodicalIF":4.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593124","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 : 2025-03-05DOI: 10.1016/j.saa.2025.125998
Zhenfang Xiao , Qiumei Huang , Wenyi Huang , Guoqiang Zhang , Dongdong Li , Zhuwei Zhang , Hao Cheng , Jun Feng , Lijun Li
The problems of poor water solubility, poor stability, and poor selectivity encountered in the determination of hexavalent chromium (Cr(VI)) in water using ZnO QDs need to be addressed. In this study, we successfully prepared Sm-doped, –NH2-modified Sm:ZnO–NH2 QDs via the sol–gel method. Sm doping was used to enhance the fluorescence intensity of ZnO QDs, while 3-aminopropyltrietoxysilane (APTEs) capping improved their water solubility and fluorescence stability. The fluorescence of Sm:ZnO–NH2 quantum dots was quenched after the addition of Cr(VI) due to the internal filtration effect(IFE), and was restored after the addition of ascorbic acid due to the redox reaction between ascorbic acid (AA) and Cr(VI). Leveraging the fluorescence response patterns of the Sm:ZnO–NH2 QDs system when exposed to Cr(VI) and AA, we developed an ’’on-off-on’’ fluorescent sensor that can specifically detect Cr(VI) and AA without interference from Cu2+ ions. The “on-off-on” fluorescent sensor exhibited a linear response to Cr(VI) concentrations ranging from 0.05 to 1.5 μg/mL, with a limit of detection (LOD) of 6.15 ng/mL. It exhibited excellent selectivity and repeatability. Furthermore, the Sm:ZnO–NH2 QDs fluorescent sensor was effectively utilized for detecting Cr(VI) in tap water, offering a new method for heavy metal detection via an “on-off-on” fluorescence switching mechanism.
{"title":"An “on-off-on” fluorescent sensor based on Sm:ZnO–NH2 QDs for hexavalent chromium detection","authors":"Zhenfang Xiao , Qiumei Huang , Wenyi Huang , Guoqiang Zhang , Dongdong Li , Zhuwei Zhang , Hao Cheng , Jun Feng , Lijun Li","doi":"10.1016/j.saa.2025.125998","DOIUrl":"10.1016/j.saa.2025.125998","url":null,"abstract":"<div><div>The problems of poor water solubility, poor stability, and poor selectivity encountered in the determination of hexavalent chromium (Cr(VI)) in water using ZnO QDs need to be addressed. In this study, we successfully prepared Sm-doped, –NH<sub>2</sub>-modified Sm:ZnO–NH<sub>2</sub> QDs via the sol–gel method. Sm doping was used to enhance the fluorescence intensity of ZnO QDs, while 3-aminopropyltrietoxysilane (APTEs) capping improved their water solubility and fluorescence stability. The fluorescence of Sm:ZnO–NH<sub>2</sub> quantum dots was quenched after the addition of Cr(VI) due to the internal filtration effect(IFE), and was restored after the addition of ascorbic acid due to the redox reaction between ascorbic acid (AA) and Cr(VI). Leveraging the fluorescence response patterns of the Sm:ZnO–NH<sub>2</sub> QDs system when exposed to Cr(VI) and AA, we developed an ’’on-off-on’’ fluorescent sensor that can specifically detect Cr(VI) and AA without interference from Cu2<sup>+</sup> ions. The “on-off-on” fluorescent sensor exhibited a linear response to Cr(VI) concentrations ranging from 0.05 to 1.5 μg/mL, with a limit of detection (LOD) of 6.15 ng/mL. It exhibited excellent selectivity and repeatability. Furthermore, the Sm:ZnO–NH<sub>2</sub> QDs fluorescent sensor was effectively utilized for detecting Cr(VI) in tap water, offering a new method for heavy metal detection via an “on-off-on” fluorescence switching mechanism.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"335 ","pages":"Article 125998"},"PeriodicalIF":4.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580000","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}
A novel fluorescence sensor utilizing label-free nitrogen self-doped carbon dots (NCDs) was developed for the sensitive, selective, and rapid determination of dichloran fungicide, popularly used in agricultural and horticultural fields. The NCDs were prepared from maleic anhydride and diethylenetriamine via a one-step pyrolysis process. They demonstrated strong blue fluorescence emission with a quantum yield of 12 %. With the addition of dichloran, the fluorescence emission of NCDs was quenched, attributed to the inner filter effect and dynamic quenching. They demonstrated outstanding sensitivity to dichloran with a linear range between 1.0 and 50.0 µM and a remarkably low detection limit of 7.6 nM, the best reported date. The sensing process could be repeatedly and rapidly generated within 30 s. Additionally, the NCDs exhibited selectivity towards dichloran amidst interferences, including common metal ions, organic chemicals, and other fungicides. The detection of dichloran in carrots, grapes, and drinking water was successfully accomplished using NCDs, yielding satisfactory recovery results ranging between 95.1 and 108.7 %. Moreover, a paper-based sensor based on NCDs as sensing probes was demonstrated to observe the fluorescence quenching towards dichloran, with a detection limit of 4.24 µM. It also showed high efficacy in distinguishing and selectively detecting dichloran against interferences. Therefore, this work contributes to the development of efficient and portable detection platforms with applications in environmental monitoring and agricultural fields.
{"title":"Novel fluorescence-based and portable detection platforms using nitrogen-doped carbon dots for environmental monitoring of dichloran fungicide","authors":"Preeyanuch Supchocksoonthorn , Pattaraporn Nuntahirun , Samita Soublerk , Chanuda Kaewkhong , Nichaphat Thongsai , Tanagorn Sangtawesin , Yao Wang , Peerasak Paoprasert","doi":"10.1016/j.saa.2025.125990","DOIUrl":"10.1016/j.saa.2025.125990","url":null,"abstract":"<div><div>A novel fluorescence sensor utilizing label-free nitrogen self-doped carbon dots (NCDs) was developed for the sensitive, selective, and rapid determination of dichloran fungicide, popularly used in agricultural and horticultural fields. The NCDs were prepared from maleic anhydride and diethylenetriamine via a one-step pyrolysis process. They demonstrated strong blue fluorescence emission with a quantum yield of 12 %. With the addition of dichloran, the fluorescence emission of NCDs was quenched, attributed to the inner filter effect and dynamic quenching. They demonstrated outstanding sensitivity to dichloran with a linear range between 1.0 and 50.0 µM and a remarkably low detection limit of 7.6 nM, the best reported date. The sensing process could be repeatedly and rapidly generated within 30 s. Additionally, the NCDs exhibited selectivity towards dichloran amidst interferences, including common metal ions, organic chemicals, and other fungicides. The detection of dichloran in carrots, grapes, and drinking water was successfully accomplished using NCDs, yielding satisfactory recovery results ranging between 95.1 and 108.7 %. Moreover, a paper-based sensor based on NCDs as sensing probes was demonstrated to observe the fluorescence quenching towards dichloran, with a detection limit of 4.24 µM. It also showed high efficacy in distinguishing and selectively detecting dichloran against interferences. Therefore, this work contributes to the development of efficient and portable detection platforms with applications in environmental monitoring and agricultural fields.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"336 ","pages":"Article 125990"},"PeriodicalIF":4.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592573","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 : 2025-03-05DOI: 10.1016/j.saa.2025.125999
Dan Tao , Suyuan Deng , Guangying Qiu , Xinglan Fu
This paper proposes a novel model updating strategy named SilkwormNet for the first time to address the sex discrimination problem of silkworm pupae with new species. SilkwormNet integrates a ResNet block, a multi-head attention mechanism, and a Schedule-Free optimization strategy. Initially, the preprocessed spectra from one species were input into SilkwormNet to establish an optimal primary model. Then, the feature extraction layers and classification head remained unfrozen and the optimal weight parameters from the basic model were applied for model updating to identify the new species. Finally, SilkwormNet used only 20 % data to update model. Uniform Manifold Approximation and Projection (UMAP) and Confusion Matrix were employed to comprehensively evaluate the results. When the basic model was built using variety 221B_403, the accuracy was highly improved after model updating, for example, for variety 871B_463 increased from 50 % to 99.22 %, for variety 9312_ShanheB increased from 74.22 % to 99.22 %; for variety FB_P71 increased from 69.53 % to 98.44 %; and for variety 7532_906 increased from 50 % to 100 %. When using just 10 % data to update the model, the range of accuracy was between 90.62 % and 95.31 %. The results of SilkwormNet were also compared with SVM, Random Forest, and 1D-CNN to further demonstrate its superiority.
{"title":"Model updating strategy study about sex identification of silkworm pupae using transfer learning and NIR spectroscopy","authors":"Dan Tao , Suyuan Deng , Guangying Qiu , Xinglan Fu","doi":"10.1016/j.saa.2025.125999","DOIUrl":"10.1016/j.saa.2025.125999","url":null,"abstract":"<div><div>This paper proposes a novel model updating strategy named SilkwormNet for the first time to address the sex discrimination problem of silkworm pupae with new species. SilkwormNet integrates a ResNet block, a multi-head attention mechanism, and a Schedule-Free optimization strategy. Initially, the preprocessed spectra from one species were input into SilkwormNet to establish an optimal primary model. Then, the feature extraction layers and classification head remained unfrozen and the optimal weight parameters from the basic model were applied for model updating to identify the new species. Finally, SilkwormNet used only 20 % data to update model. Uniform Manifold Approximation and Projection (UMAP) and Confusion Matrix were employed to comprehensively evaluate the results. When the basic model was built using variety 221B_403, the accuracy was highly improved after model updating, for example, for variety 871B_463 increased from 50 % to 99.22 %, for variety 9312_ShanheB increased from 74.22 % to 99.22 %; for variety FB_P71 increased from 69.53 % to 98.44 %; and for variety 7532_906 increased from 50 % to 100 %. When using just 10 % data to update the model, the range of accuracy was between 90.62 % and 95.31 %. The results of SilkwormNet were also compared with SVM, Random Forest, and 1D-CNN to further demonstrate its superiority.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"335 ","pages":"Article 125999"},"PeriodicalIF":4.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580152","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 : 2025-03-04DOI: 10.1016/j.saa.2025.125984
S. Olsztyńska-Janus , M.A. Czarnecki
Every year, more and more adults and children with severe cardiac and/or respiratory failure require connection to extracorporeal circulation (ECC). Despite a life-saving role in emergency settings, the use of ECC is associated with several serious complications, which result from structural changes in the plasma components. As yet, the molecular mechanism of these changes was not well recognized, and therefore we undertook the first spectroscopic study of structural changes in plasma during ECC. Vibrational spectroscopy coupled with two-dimensional correlation spectroscopy (2D-COS) is a powerful tool for elucidation of variations at a molecular level. The spectra of animal plasma were recorded by ATR-IR (Attenuated Total Reflection-Infrared) technique, which enables measurements of strongly absorbing samples in a non-destructive way. Moving-window and 2D-COS methods were used to obtain more detailed information about the correlation between spectral features and vibrations of functional groups. A comprehensive analysis of variations in the main plasma components requires using bands from both polar (NH, OH, CO, and CO) and non-polar groups (aliphatic and aromatic moieties). Of particular interest is the effect of the state of water on the structure and intermolecular interactions of the plasma under ECC.
{"title":"Effect of extracorporeal circulation on structure of main components of animal plasma – ATR-IR and 2D-COS studies: Part I","authors":"S. Olsztyńska-Janus , M.A. Czarnecki","doi":"10.1016/j.saa.2025.125984","DOIUrl":"10.1016/j.saa.2025.125984","url":null,"abstract":"<div><div>Every year, more and more adults and children with severe cardiac and/or respiratory failure require connection to extracorporeal circulation (ECC). Despite a life-saving role in emergency settings, the use of ECC is associated with several serious complications, which result from structural changes in the plasma components. As yet, the molecular mechanism of these changes was not well recognized, and therefore we undertook the first spectroscopic study of structural changes in plasma during ECC. Vibrational spectroscopy coupled with two-dimensional correlation spectroscopy (2D-COS) is a powerful tool for elucidation of variations at a molecular level. The spectra of animal plasma were recorded by ATR-IR (Attenuated Total Reflection-Infrared) technique, which enables measurements of strongly absorbing samples in a non-destructive way. Moving-window and 2D-COS methods were used to obtain more detailed information about the correlation between spectral features and vibrations of functional groups. A comprehensive analysis of variations in the main plasma components requires using bands from both polar (<img>NH, <img>OH, <img>CO, and C<img>O) and non-polar groups (aliphatic and aromatic moieties). Of particular interest is the effect of the state of water on the structure and intermolecular interactions of the plasma under ECC.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"335 ","pages":"Article 125984"},"PeriodicalIF":4.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611020","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}
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