Pub Date : 2025-01-31DOI: 10.1016/j.saa.2025.125809
Xiangying Sun , Jianping Zeng , Xiaopeng Wang , Huaiqian Wang
Delayed fluorescence of organic dye materials with visible light excitation has expansive application prospects. Because of the coplanarity of fluorescent dyes and rigid matrix, the reverse cross rate between the systems is slow and the fluorescence life is long. Therefore, once the fluorescent dyes are assembled in the polymer matrix, the delayed fluorescence with strong intensity and long lifetime will be produced. Herein, terephthalic acid (PTA) with melamine (MA) were assembled into the rigid matrix of PTA-MA, delayed fluorescence of acridine dyes induced based on the energy transfer from PTA-MA to acridine dyes. The long afterglow of PTA-MA@AO with about 7 s under the UV light and visible light can be produced. The mechanism of dye delayed fluorescence, and the effects of dye type on optical properties were studied. PTA-MA@acridine dyes with different long afterglow properties were used to anti-counterfeiting applications.
{"title":"Delayed fluorescence of acridine dyes induced by supramolecular assembly of terephthalic acid and melamine","authors":"Xiangying Sun , Jianping Zeng , Xiaopeng Wang , Huaiqian Wang","doi":"10.1016/j.saa.2025.125809","DOIUrl":"10.1016/j.saa.2025.125809","url":null,"abstract":"<div><div>Delayed fluorescence of organic dye materials with visible light excitation has expansive application prospects. Because of the coplanarity of fluorescent dyes and rigid matrix, the reverse cross rate between the systems is slow and the fluorescence life is long. Therefore, once the fluorescent dyes are assembled in the polymer matrix, the delayed fluorescence with strong intensity and long lifetime will be produced. Herein, terephthalic acid (PTA) with melamine (MA) were assembled into the rigid matrix of PTA-MA, delayed fluorescence of acridine dyes induced based on the energy transfer from PTA-MA to acridine dyes. The long afterglow of PTA-MA@AO with about 7 s under the UV light and visible light can be produced. The mechanism of dye delayed fluorescence, and the effects of dye type on optical properties were studied. PTA-MA@acridine dyes with different long afterglow properties were used to anti-counterfeiting applications.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"332 ","pages":"Article 125809"},"PeriodicalIF":4.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143314890","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 : 2025-01-31DOI: 10.1016/j.saa.2025.125827
Pingping Wang , Yongjun Song , Ke Zhang, Mingxing Tian, Lei He
Thermally-activated delayed fluorescence (TADF) materials have emerged as next-generation emitters for organic light-emitting diodes (OLEDs). The donor-σ-acceptor molecule is a promising paradigm for developing TADF, but its radiative decay rate (kr,s) and photoluminescent efficiency (ФPL) require large improvements, due to weak intramolecular charge-transfer (CT). Here, efficient donor-σ-acceptor emitters (1–3) with strengthened intramolecular CT are developed by directly linking the donor and acceptor with a short alkyl chain. 9,9-dimethyl-9,10-dihydroacridine and 2,4,6-triphenyl-1,3,5-triazine are employed as the donor and acceptor, respectively, and –CH2– (for 1), –CH2CH2– (for 2) and –CH2CH2CH2– (for 3) are employed as the σ-linkers. The chemical structures of 1–3 have been verified by X-ray crystallography. In dilute solution and lightly doped films, emitters 1–3 show considerably strong intramolecular CT, due to the σ–π hyperconjugation between the donor/acceptor and the alkyl σ-linker. In the 20 wt.% doped films, emitters 1–3 show green–blue TADF with combined intra- and inter-molecular CT, with high ФPLkr,s and reverse intersystem crossing rates up to 0.91, 8.5 × 106 s−1 and 2.6 × 106 s−1, respectively. OLEDs based on emitters 1–3 show green–blue emission with high external quantum efficiencies (EQEs) over 20 %. A hyperfluorescent OLED with emitter 3 as the sensitizer and a typical multiple resonance emitter (DtBuCzB) as the terminal emitter shows narrowband blue-green emission with a high EQE of 28.1 %.
{"title":"Efficient donor-σ-acceptor emitters with strengthened intramolecular charge-transfer and their use for high-efficiency organic light-emitting diodes","authors":"Pingping Wang , Yongjun Song , Ke Zhang, Mingxing Tian, Lei He","doi":"10.1016/j.saa.2025.125827","DOIUrl":"10.1016/j.saa.2025.125827","url":null,"abstract":"<div><div>Thermally-activated delayed fluorescence (TADF) materials have emerged as next-generation emitters for organic light-emitting diodes (OLEDs). The donor-σ-acceptor molecule is a promising paradigm for developing TADF, but its radiative decay rate (<em>k</em><sub>r,s</sub>) and photoluminescent efficiency (Ф<sub>PL</sub>) require large improvements, due to weak intramolecular charge-transfer (CT). Here, efficient donor-σ-acceptor emitters (<strong>1</strong>–<strong>3</strong>) with strengthened intramolecular CT are developed by directly linking the donor and acceptor with a short alkyl chain. 9,9-dimethyl-9,10-dihydroacridine and 2,4,6-triphenyl-1,3,5-triazine are employed as the donor and acceptor, respectively, and –CH<sub>2</sub>– (for <strong>1</strong>), –CH<sub>2</sub>CH<sub>2</sub>– (for <strong>2</strong>) and –CH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>– (for <strong>3</strong>) are employed as the σ-linkers. The chemical structures of <strong>1</strong>–<strong>3</strong> have been verified by X-ray crystallography. In dilute solution and lightly doped films, emitters <strong>1</strong>–<strong>3</strong> show considerably strong intramolecular CT, due to the σ–π hyperconjugation between the donor/acceptor and the alkyl σ-linker. In the 20 wt.% doped films, emitters <strong>1</strong>–<strong>3</strong> show green–blue TADF with combined intra- and inter-molecular CT, with high Ф<sub>PL</sub> <em>k</em><sub>r,s</sub> and reverse intersystem crossing rates up to 0.91, 8.5 × 10<sup>6</sup> s<sup>−1</sup> and 2.6 × 10<sup>6</sup> s<sup>−1</sup>, respectively. OLEDs based on emitters <strong>1</strong>–<strong>3</strong> show green–blue emission with high external quantum efficiencies (EQEs) over 20 %. A hyperfluorescent OLED with emitter <strong>3</strong> as the sensitizer and a typical multiple resonance emitter (DtBuCzB) as the terminal emitter shows narrowband blue-green emission with a high EQE of 28.1 %.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"332 ","pages":"Article 125827"},"PeriodicalIF":4.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094881","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 : 2025-01-31DOI: 10.1016/j.saa.2025.125804
Yuanfu Zhang , Xue Zhao , Lei Jin , Wenyu Xu , Xianfeng Shao , Yaqi Liu , Yawei Chen , Federico Rosei
We present the design and synthesis of a gold nanoparticle-wood nanohybrid (AuNPs@Wood), synthesized via the in-situ growth of gold nanoparticles (AuNPs) within a hierarchical wood flour nanostructure under mild conditions. The AuNPs@Wood exhibited remarkable peroxidase-like activity, attributed to the unique hierarchical architecture of the wood flour. Furthermore, the use of AuNPs@Wood in conjunction with T-rich DNA (P1) results in the development of a label-free colorimetric approach for detecting mercury ions. The peroxidase-like activity of the AuNPs@Wood–P1 system was found to increase with rising concentrations of Hg (II), demonstrating a linear response to Hg (II) concentration with a correlation coefficient of 0.9917. The detection limit for Hg (II) was determined to be 0.016 μM based on three times the standard deviation (σ). Additionally, sensing Hg2+ ions remained unaffected by other metal ions, underscoring the exceptional selectivity of AuNPs@Wood–P1. In comparison to traditional methods, this approach offers advantages such as high selectivity, sensitivity, cost-effectiveness, and ease of operation without requiring complex instrumentation, thereby presenting significant potential for biosensing applications.
{"title":"Gold nanoparticles-wood nanohybrid as peroxidase-like for simple and selective detection of mercury ion","authors":"Yuanfu Zhang , Xue Zhao , Lei Jin , Wenyu Xu , Xianfeng Shao , Yaqi Liu , Yawei Chen , Federico Rosei","doi":"10.1016/j.saa.2025.125804","DOIUrl":"10.1016/j.saa.2025.125804","url":null,"abstract":"<div><div>We present the design and synthesis of a gold nanoparticle-wood nanohybrid (AuNPs@Wood), synthesized via the <em>in-situ</em> growth of gold nanoparticles (AuNPs) within a hierarchical wood flour nanostructure under mild conditions. The AuNPs@Wood exhibited remarkable peroxidase-like activity, attributed to the unique hierarchical architecture of the wood flour. Furthermore, the use of AuNPs@Wood in conjunction with T-rich DNA (P1) results in the development of a label-free colorimetric approach for detecting mercury ions. The peroxidase-like activity of the AuNPs@Wood–P1 system was found to increase with rising concentrations of Hg (II), demonstrating a linear response to Hg (II) concentration with a correlation coefficient of 0.9917. The detection limit for Hg (II) was determined to be 0.016 μM based on three times the standard deviation (σ). Additionally, sensing Hg<sup>2+</sup> ions remained unaffected by other metal ions, underscoring the exceptional selectivity of AuNPs@Wood–P1. In comparison to traditional methods, this approach offers advantages such as high selectivity, sensitivity, cost-effectiveness, and ease of operation without requiring complex instrumentation, thereby presenting significant potential for biosensing applications.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"332 ","pages":"Article 125804"},"PeriodicalIF":4.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349446","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 : 2025-01-31DOI: 10.1016/j.saa.2025.125831
Shu-Long He , Guo-Bin Wang , Xue-Li Cheng , Lin-Lin Han , Wei Pan , Han-Yang Zou , Shi-Li Shen , Xian-Hong Pang , Yan Zhu
Mitochondria are crucial energy-supplying organelles that support cellular activities and play vital roles in cell metabolism, aging, autophagy, and apoptosis. Abnormal viscosity can alter the mitochondrial microenvironment, disrupt normal mitochondrial function, and lead to disease. To address this, we designed and developed two aggregation-induced emission–twisted intramolecular charge transfer fluorescent probes, namely, (E)-1,1,3-trimethyl-2-(4-(1,2,2-triphenylvinyl)styryl)-1H-benzo[e]indol-3-ium (HSL-1) and (E)-2-(4-(di-p-tolylamino)styryl)-1,3,3-trimethyl-1H-benzo[e]indol-3-ium (HSL-2). In vitro fluorescence detection revealed that both HSL-1 and HSL-2 were sensitive to viscosity and demonstrated a strong log-linear relationship, with linear coefficients of 0.982 and 0.980, respectively. Notably, the responses of HSL-1 and HSL-2 to viscosity changes were unaffected by pH, polarity, or interfering ions. HSL-1 exhibited stronger resistance to background interference than HSL-2 and significantly enhanced fluorescence intensity; thus, it was selected for cell experiments and animal fluorescence intensity assessments. Furthermore, HSL-1 showed excellent biocompatibility, enabling real-time detection of mitochondrial viscosity changes and identification of viscosity abnormalities triggered by mitophagy in HeLa cells. It could also monitor changes in mitochondrial viscosity in zebrafish. In conclusion, HSL-1 is a valuable tool for studying viscosity and understanding diseases associated with abnormal mitochondrial viscosity.
{"title":"Aggregation-induced emission–twisted intramolecular charge transfer-activated fluorescent probe for analyzing mitochondrial viscosity in cells and zebrafish","authors":"Shu-Long He , Guo-Bin Wang , Xue-Li Cheng , Lin-Lin Han , Wei Pan , Han-Yang Zou , Shi-Li Shen , Xian-Hong Pang , Yan Zhu","doi":"10.1016/j.saa.2025.125831","DOIUrl":"10.1016/j.saa.2025.125831","url":null,"abstract":"<div><div>Mitochondria are crucial energy-supplying organelles that support cellular activities and play vital roles in cell metabolism, aging, autophagy, and apoptosis. Abnormal viscosity can alter the mitochondrial microenvironment, disrupt normal mitochondrial function, and lead to disease. To address this, we designed and developed two aggregation-induced emission–twisted intramolecular charge transfer fluorescent probes, namely, (<em>E</em>)-1,1,3-trimethyl-2-(4-(1,2,2-triphenylvinyl)styryl)-1H-benzo[e]indol-3-ium (HSL-1) and (<em>E</em>)-2-(4-(di-p-tolylamino)styryl)-1,3,3-trimethyl-1H-benzo[e]indol-3-ium (HSL-2). <em>In vitro</em> fluorescence detection revealed that both HSL-1 and HSL-2 were sensitive to viscosity and demonstrated a strong log-linear relationship, with linear coefficients of 0.982 and 0.980, respectively. Notably, the responses of HSL-1 and HSL-2 to viscosity changes were unaffected by pH, polarity, or interfering ions. HSL-1 exhibited stronger resistance to background interference than HSL-2 and significantly enhanced fluorescence intensity; thus, it was selected for cell experiments and animal fluorescence intensity assessments. Furthermore, HSL-1 showed excellent biocompatibility, enabling real-time detection of mitochondrial viscosity changes and identification of viscosity abnormalities triggered by mitophagy in HeLa cells. It could also monitor changes in mitochondrial viscosity in zebrafish. In conclusion, HSL-1 is a valuable tool for studying viscosity and understanding diseases associated with abnormal mitochondrial viscosity.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"332 ","pages":"Article 125831"},"PeriodicalIF":4.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143314893","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}
Herein, we present a paradigm of a flexible molecular system for simultaneous discernment of Ni2+ and Cd2+, depending on distinct chemical coordination manners. By incorporating two functional pyridine groups at different positions on the flexible DPAC framework (9,14-diphenyl-9,14-Dihydrodibenzo [a,c]phenazine), two derivatives are prepared as 27Py-DPAC and 36Py-DPAC. The results show that 27Py-DPAC can chemically coordinate with Ni2+ (intermolecular coordination) and Cd2+ (intramolecular coordination), generating fluorescence turn-off and -on behaviors, respectively. The key factors leading to the different coordination ways are the ionic radius and the substituted positions of pyridine groups. Demonstrably, 36Py-DPAC can respond to Ni2+ abiding by the principle of the 27Py-DPAC sensor, but it cannot sense Cd2+ because of the difficulty in forming an effective intramolecular coordination resulted from the large distance between two nitrogen atoms on pyridine and the central heterocyclic ring. Based on the ionic response properties of the two compounds, logic circuits were developed to simulate logical operations and facilitate ion detection. This research expands the applicability of flexible polycyclic conjugated molecules in chemical sensing and underscores the influence of different modification sites of functional groups on ion binding mechanisms.
{"title":"A flexible polycyclic chemosensor for simultaneous discernment of Ni2+ and Cd2+ depending on distinct coordination modes","authors":"Ziyu Chen, Qianxin Long, Wen Li, Zhiyun Zhang, Jianhua Su, Lifang Guo","doi":"10.1016/j.saa.2025.125830","DOIUrl":"10.1016/j.saa.2025.125830","url":null,"abstract":"<div><div>Herein, we present a paradigm of a flexible molecular system for simultaneous discernment of Ni<sup>2+</sup> and Cd<sup>2+</sup>, depending on distinct chemical coordination manners. By incorporating two functional pyridine groups at different positions on the flexible DPAC framework (9,14-diphenyl-9,14-Dihydrodibenzo [a,c]phenazine), two derivatives are prepared as <strong>27Py-DPAC</strong> and <strong>36Py-DPAC</strong>. The results show that <strong>27Py-DPAC</strong> can chemically coordinate with Ni<sup>2+</sup> (intermolecular coordination) and Cd<sup>2+</sup> (intramolecular coordination), generating fluorescence turn-off and -on behaviors, respectively. The key factors leading to the different coordination ways are the ionic radius and the substituted positions of pyridine groups. Demonstrably, <strong>36Py-DPAC</strong> can respond to Ni<sup>2+</sup> abiding by the principle of the <strong>27Py-DPAC</strong> sensor, but it cannot sense Cd<sup>2+</sup> because of the difficulty in forming an effective intramolecular coordination resulted from the large distance between two nitrogen atoms on pyridine and the central heterocyclic ring. Based on the ionic response properties of the two compounds, logic circuits were developed to simulate logical operations and facilitate ion detection. This research expands the applicability of flexible polycyclic conjugated molecules in chemical sensing and underscores the influence of different modification sites of functional groups on ion binding mechanisms.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"332 ","pages":"Article 125830"},"PeriodicalIF":4.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350393","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}
Heterocycle compounds that contain nitrogen play important roles in astrobiology and terrestrial biology as a building block of nucleic acid. Nitrogen inclusion in polycyclic aromatic hydrocarbons (PAHs) is also proposed to account for the emission band at 6.2 µm observed in the interstellar medium (ISM). This work comprehensively studies the theoretical microwave, infrared (IR), and ultraviolet (UV)/visible spectra of aromatic and N-heterocycles in the gas phase and water solvent. In this study, one tricyclic tetrahydroquinoline (THQ) and two fused polycyclic quinolines, and their carboxylic acid substitutions in their neutral and ionic states are reported for the first time. All the calculations are performed at the B3LYP/aug-cc-pVTZ level of theory using the Gaussian 16. The rotational constants are obtained at this level of theory, which are further used to calculate the rotational spectra and their transitions. The IR spectra of these molecules are also reported to discuss possible carriers of the aromatic infrared bands (AIBs) observed in the ISM. The electronic absorption spectra of the molecule are also obtained using the time-dependent density functional theory (TD-DFT) at the same level of theory, allowing us to determine the energy gap between the Highest Occupied Molecular Orbitals (HOMO) and Lowest Unoccupied Molecular Orbitals (LUMO) and discuss their stability. We further estimate the transition wavelength, oscillator strength, and symmetry using the AOMix. This study contributes to understanding the physicochemical properties of the building blocks of genetic molecules.
{"title":"Theoretical study of aromatic and N-heterocycles: Potential carriers of interstellar aromatic infrared bands","authors":"Venkata Lakshmi Karri , Takashi Onaka , Mahadevappa Naganathappa","doi":"10.1016/j.saa.2025.125811","DOIUrl":"10.1016/j.saa.2025.125811","url":null,"abstract":"<div><div>Heterocycle compounds that contain nitrogen play important roles in astrobiology and terrestrial biology as a building block of nucleic acid. Nitrogen inclusion in polycyclic aromatic hydrocarbons (PAHs) is also proposed to account for the emission band at 6.2 µm observed in the interstellar medium (ISM). This work comprehensively studies the theoretical microwave, infrared (IR), and ultraviolet (UV)/visible spectra of aromatic and N-heterocycles in the gas phase and water solvent. In this study, one tricyclic tetrahydroquinoline (THQ) and two fused polycyclic quinolines, and their carboxylic acid substitutions in their neutral and ionic states are reported for the first time. All the calculations are performed at the B3LYP/aug-cc-pVTZ level of theory using the Gaussian 16. The rotational constants are obtained at this level of theory, which are further used to calculate the rotational spectra and their transitions. The IR spectra of these molecules are also reported to discuss possible carriers of the aromatic infrared bands (AIBs) observed in the ISM. The electronic absorption spectra of the molecule are also obtained using the time-dependent density functional theory (TD-DFT) at the same level of theory, allowing us to determine the energy gap between the Highest Occupied Molecular Orbitals (HOMO) and Lowest Unoccupied Molecular Orbitals (LUMO) and discuss their stability. We further estimate the transition wavelength, oscillator strength, and symmetry using the AOMix. This study contributes to understanding the physicochemical properties of the building blocks of genetic molecules.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"332 ","pages":"Article 125811"},"PeriodicalIF":4.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350390","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 : 2025-01-31DOI: 10.1016/j.saa.2025.125828
Dragos Lucian Isac , Emilian Rosca , Anton Airinei , Elena Laura Ursu , Razvan Puf , Isabela Costinela Man , Andrei Neamtu , Aatto Laaksonen
Raman spectroscopy can provide highly sensitive and detailed information about the structural fingerprint of molecules, enabling their identification. In this study, our aim is to understand the enhanced intensity observed in experimental Raman measurements. Five azobenzene derivatives were selected, each substituted with different functional groups, for both experimental and theoretical investigations. To reproduce the experimental trend, we employed various levels of theory using the QM-DFT approach. Theoretical results were compared to experimental data through both qualitative and quantitative analyses. A good correlation between theoretical and experimental results was achieved when considering electronic transitions to predict the theoretical Raman spectra and interpret the experimental data. Our theoretical results indicate that even dark (nπ*) transitions, which are forbidden and have an oscillator strength close to zero, can have a signature in the Raman spectra due to the resonance effect with incident energy. Additionally, the vibrational modes stimulated by the presence of ππ* bright states, being at the pre-resonance with the incident energy, was clearly separated from the vibrational frequencies of the dark states, which was evinced in the Raman fingerprint. Theoretical Raman spectra of azobenzene derivatives, substituted with push–pull moieties, revealed contributions from the charge transfer transitions (nπ*CT, ππ*CT) as well as back-donation of electron density, observed for the first time in an azobenzene derivative. Our protocol, proposing a quantitative and qualitative overlap between theoretical and experimental data, confirms the presence of combination modes between vibrational levels and electronically excited states.
{"title":"Signature of electronically excited states in Raman spectra of azobenzene derivatives. Computational and experimental approaches","authors":"Dragos Lucian Isac , Emilian Rosca , Anton Airinei , Elena Laura Ursu , Razvan Puf , Isabela Costinela Man , Andrei Neamtu , Aatto Laaksonen","doi":"10.1016/j.saa.2025.125828","DOIUrl":"10.1016/j.saa.2025.125828","url":null,"abstract":"<div><div>Raman spectroscopy can provide highly sensitive and detailed information about the structural fingerprint of molecules, enabling their identification. In this study, our aim is to understand the enhanced intensity observed in experimental Raman measurements. Five azobenzene derivatives were selected, each substituted with different functional groups, for both experimental and theoretical investigations. To reproduce the experimental trend, we employed various levels of theory using the QM-DFT approach. Theoretical results were compared to experimental data through both qualitative and quantitative analyses. A good correlation between theoretical and experimental results was achieved when considering electronic transitions to predict the theoretical Raman spectra and interpret the experimental data. Our theoretical results indicate that even dark (nπ*) transitions, which are forbidden and have an oscillator strength close to zero, can have a signature in the Raman spectra due to the resonance effect with incident energy. Additionally, the vibrational modes stimulated by the presence of ππ* bright states, being at the pre-resonance with the incident energy, was clearly separated from the vibrational frequencies of the dark states, which was evinced in the Raman fingerprint. Theoretical Raman spectra of azobenzene derivatives, substituted with push–pull moieties, revealed contributions from the charge transfer transitions (nπ*CT, ππ*CT) as well as back-donation of electron density, observed for the first time in an azobenzene derivative. Our protocol, proposing a quantitative and qualitative overlap between theoretical and experimental data, confirms the presence of combination modes between vibrational levels and electronically excited states.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"332 ","pages":"Article 125828"},"PeriodicalIF":4.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-31DOI: 10.1016/j.saa.2025.125840
Siyuan Li , Liuyan Zhou , Xiaofei Wang , Rongrong Ren , Hanqing Li , Yanfei Mao , Jingxian Liu , Lixia Li , Yan Cao
Amikacin (AMK) is a semisynthetic antibiotic used in the treatment of gram-negative bacterial infections and has a narrow therapeutic index. Individualized treatment of amikacin under the guidance of therapeutic drug monitoring (TDM) is important to reduce the occurrence of toxicity and improve clinical efficacy. Current TDM techniques for AMK, such as chromatographic technology and immunoassay, are conducted in central labs using specialized equipment. However, the extensive time and costs involved hinder the application of AMK detection in medical practices. In the present study, a novel surface plasmon resonance (SPR) biosensor for detecting the concentration of AMK in human serum samples was developed and validated. The detection range of SPR method was 0.125 ∼ 8 ng/ml, and the limit of detection was 0.035 ± 0.004 ng/ml. The intra- and inter-day accuracy of SPR was 98 %–105 % and 97 %–110 %, respectively, which met the analytical requirements. The consistency evaluation with the high-performance liquid chromatography (HPLC) method shows that the SPR biosensor is reliable for quantification of AMK. This work is a foundation towards the development of a label-free, real-time, accurate, low cost, and simple method for future TDM, and will help clinicians to optimize dosing regimens thus to maximize the clinical effect and minimize the toxicity of these drugs.
{"title":"Antibody-based surface plasmon resonance sensor platform for monitoring amikacin drug concentrations in human serum samples","authors":"Siyuan Li , Liuyan Zhou , Xiaofei Wang , Rongrong Ren , Hanqing Li , Yanfei Mao , Jingxian Liu , Lixia Li , Yan Cao","doi":"10.1016/j.saa.2025.125840","DOIUrl":"10.1016/j.saa.2025.125840","url":null,"abstract":"<div><div>Amikacin (AMK) is a semisynthetic antibiotic used in the treatment of gram-negative bacterial infections and has a narrow therapeutic index. Individualized treatment of amikacin under the guidance of therapeutic drug monitoring (TDM) is important to reduce the occurrence of toxicity and improve clinical efficacy. Current TDM techniques for AMK, such as chromatographic technology and immunoassay, are conducted in central labs using specialized equipment. However, the extensive time and costs involved hinder the application of AMK detection in medical practices. In the present study, a novel surface plasmon resonance (SPR) biosensor for detecting the concentration of AMK in human serum samples was developed and validated. The detection range of SPR method was 0.125 ∼ 8 ng/ml, and the limit of detection was 0.035 ± 0.004 ng/ml. The intra- and inter-day accuracy of SPR was 98 %–105 % and 97 %–110 %, respectively, which met the analytical requirements. The consistency evaluation with the high-performance liquid chromatography (HPLC) method shows that the SPR biosensor is reliable for quantification of AMK. This work is a foundation towards the development of a label-free, real-time, accurate, low cost, and simple method for future TDM, and will help clinicians to optimize dosing regimens thus to maximize the clinical effect and minimize the toxicity of these drugs.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"333 ","pages":"Article 125840"},"PeriodicalIF":4.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350207","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 : 2025-01-30DOI: 10.1016/j.saa.2025.125818
Yiheng Yuan , Xishun Peng , Cunwei Wang , Haili Zhang , Caizhen Zu , Zhangyu Zhou , Zhongchen Bai
The threats of antibiotic residues to human health and the environment have become more and more severe due to the overuse of antibiotics in agriculture. Here, multi-walled carbon nanotubes (MWCNTs) were used to prepare MWCNTs@ZnO/Ag substrate by a simple two-step electrochemical deposition process to detect the enrofloxacin (ENR) residues in pork. The coral-like MWCNTs with a large surface area could promote ENR adsorption and provide more sites for growing the ZnO/Ag nanostructures. Moreover, ZnO/Ag nanostructures could not only facilitate the electron transfer to increase Raman intensity but also improve the stability of MWCNTs@ZnO/Ag substrate. Thus, the MWCNTs@ZnO/Ag substrate could easily recognize ENR molecules at a low concentration of 5 × 10−10 M due to the stronger charge transfer effect between the substrates and analytes. In addition, the limit of detection of ENR residues in pork samples by using MWCNTs@ZnO/Ag substrate was up to 5.87 nM. The SERS sensor of the MWCNTs@ZnO/Ag substrate has a high sensitivity and long-term stability for the detection of antibiotic residues in food, which could be applied in fields of food safety.
{"title":"Surface-enhanced Raman scattering sensor based on MWCNTs@ZnO/Ag to detect the enrofloxacin in pork","authors":"Yiheng Yuan , Xishun Peng , Cunwei Wang , Haili Zhang , Caizhen Zu , Zhangyu Zhou , Zhongchen Bai","doi":"10.1016/j.saa.2025.125818","DOIUrl":"10.1016/j.saa.2025.125818","url":null,"abstract":"<div><div>The threats of antibiotic residues to human health and the environment have become more and more severe due to the overuse of antibiotics in agriculture. Here, multi-walled carbon nanotubes (MWCNTs) were used to prepare MWCNTs@ZnO/Ag substrate by a simple two-step electrochemical deposition process to detect the enrofloxacin (ENR) residues in pork. The coral-like MWCNTs with a large surface area could promote ENR adsorption and provide more sites for growing the ZnO/Ag nanostructures. Moreover, ZnO/Ag nanostructures could not only facilitate the electron transfer to increase Raman intensity but also improve the stability of MWCNTs@ZnO/Ag substrate. Thus, the MWCNTs@ZnO/Ag substrate could easily recognize ENR molecules at a low concentration of 5 × 10<sup>−10</sup> M due to the stronger charge transfer effect between the substrates and analytes. In addition, the limit of detection of ENR residues in pork samples by using MWCNTs@ZnO/Ag substrate was up to 5.87 nM. The SERS sensor of the MWCNTs@ZnO/Ag substrate has a high sensitivity and long-term stability for the detection of antibiotic residues in food, which could be applied in fields of food safety.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"332 ","pages":"Article 125818"},"PeriodicalIF":4.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103895","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 : 2025-01-30DOI: 10.1016/j.saa.2025.125826
Yuzhu Sun , Mengle Yang , Tao Liu , Jun Ying , Aixiang Tian , Xiuli Wang
Multi-stimuli-responsive materials have garnered widespread attention due to their exceptional potential in various applications, including optical anti-counterfeiting devices, sensor technology, and information storage materials. In this study, we demonstrate the synthesis of four polyoxometalates/viologens (POMs/Vios)-based compounds featuring remarkable color-changing performance, namely, [Zn6(HL)2(H2O)20(TeMo6O24)3]·6H2O (1), [Co6(HL)2(H2O)20(TeMo6O24)3]·4H2O (2), [Zn(TeMo6O24)(H2O)2]·L2·6H2O (3), [Co(TeMo6O24)(H2O)2]·L2·6H2O (4) (L·Cl2 = 1,1′–[1,3–phenylenebis(methylene)] bis–(4,4′–bipyridine) dichloride). Compounds 1, 3, and 4 exhibit rapid and reversible photochromic properties, making them suitable for applications in erasable inkless printing and information storage. Furthermore, hydrogels based on these compounds can act as ultraviolet detectors. An innovative electrochromic (EC) hydrogel can be prepared by incorporating compounds 1–4 into polyacrylamide (PAAm). The integrated electrochromic devices (ECDs) based on EC hydrogel can precisely switch between the coloring and fading states through the precise control of different voltages. They are characterized by simple operation, high sensitivity, and low-voltage drive (ranging from –0.21 to –0.35 V). Additionally, compounds 1–4 act as highly efficient organic amine gas sensors. This work is anticipated to provide inspiration for the systematic design and development of diverse color-changing materials that respond to multiple external stimuli.
{"title":"Four multi-stimuli-responsive color-changing materials based on Anderson-viologens for erasable inkless printing, UV detectors and gradient detection of amine gases","authors":"Yuzhu Sun , Mengle Yang , Tao Liu , Jun Ying , Aixiang Tian , Xiuli Wang","doi":"10.1016/j.saa.2025.125826","DOIUrl":"10.1016/j.saa.2025.125826","url":null,"abstract":"<div><div>Multi-stimuli-responsive materials have garnered widespread attention due to their exceptional potential in various applications, including optical anti-counterfeiting devices, sensor technology, and information storage materials. In this study, we demonstrate the synthesis of four polyoxometalates/viologens (POMs/Vios)-based compounds featuring remarkable color-changing performance, namely, [Zn<sub>6</sub>(HL)<sub>2</sub>(H<sub>2</sub>O)<sub>20</sub>(TeMo<sub>6</sub>O<sub>24</sub>)<sub>3</sub>]·6H<sub>2</sub>O (<strong>1</strong>), [Co<sub>6</sub>(HL)<sub>2</sub>(H<sub>2</sub>O)<sub>20</sub>(TeMo<sub>6</sub>O<sub>24</sub>)<sub>3</sub>]·4H<sub>2</sub>O (<strong>2</strong>), [Zn(TeMo<sub>6</sub>O<sub>24</sub>)(H<sub>2</sub>O)<sub>2</sub>]·L<sub>2</sub>·6H<sub>2</sub>O (<strong>3</strong>), [Co(TeMo<sub>6</sub>O<sub>24</sub>)(H<sub>2</sub>O)<sub>2</sub>]·L<sub>2</sub>·6H<sub>2</sub>O (<strong>4</strong>) (L·Cl<sub>2</sub> = 1,1′–[1,3–phenylenebis(methylene)] bis–(4,4′–bipyridine) dichloride). Compounds <strong>1</strong>, <strong>3</strong>, and <strong>4</strong> exhibit rapid and reversible photochromic properties, making them suitable for applications in erasable inkless printing and information storage. Furthermore, hydrogels based on these compounds can act as ultraviolet detectors. An innovative electrochromic (EC) hydrogel can be prepared by incorporating compounds <strong>1</strong>–<strong>4</strong> into polyacrylamide (PAAm). The integrated electrochromic devices (ECDs) based on EC hydrogel can precisely switch between the coloring and fading states through the precise control of different voltages. They are characterized by simple operation, high sensitivity, and low-voltage drive (ranging from –0.21 to –0.35 V). Additionally, compounds <strong>1</strong>–<strong>4</strong> act as highly efficient organic amine gas sensors. This work is anticipated to provide inspiration for the systematic design and development of diverse color-changing materials that respond to multiple external stimuli.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"332 ","pages":"Article 125826"},"PeriodicalIF":4.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103901","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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