Pub Date : 2026-01-03DOI: 10.1016/j.saa.2026.127435
Zhiwei Lv , Shuangshuang Gao , Ting Li , Hongzhuan Xuan
This study aims to investigate the effects of pH levels on the binding ability and antioxidant activity of major royal jelly protein 1 (MRJP1) with quercetin (Q) and to elucidate the interaction mechanisms using multi-spectroscopy and molecular docking analysis. The results showed that the quenching of MRJP1 by Q was governed by a static quenching mechanism at pH 5.5, 7.0, and 8.5. MRJP1 exhibited a higher binding affinity for Q at pH 8.5 and 7.0 than at pH 5.5. Hydrophilic interaction was the main driving force for the formation of the MRJP1–Q complex at pH 5.5–8.5. Molecular modeling further revealed that Q preferred to interact with the central domain of MRJP1 across all tested pH conditions. Importantly, the formation of the MRJP1–Q complex increased the apparent solubility of Q and synergistically enhanced the ABTS+ radical scavenging capacities of both components. These findings suggest that the MRJP1–Q complex represents a nutritionally valuable substance with potent antioxidant capabilities, holding promise for functional food and nutraceutical applications.
{"title":"Binding effects of quercetin on the structural and functional properties of major royal jelly protein 1 under different pH conditions","authors":"Zhiwei Lv , Shuangshuang Gao , Ting Li , Hongzhuan Xuan","doi":"10.1016/j.saa.2026.127435","DOIUrl":"10.1016/j.saa.2026.127435","url":null,"abstract":"<div><div>This study aims to investigate the effects of pH levels on the binding ability and antioxidant activity of major royal jelly protein 1 (MRJP1) with quercetin (Q) and to elucidate the interaction mechanisms using multi-spectroscopy and molecular docking analysis. The results showed that the quenching of MRJP1 by Q was governed by a static quenching mechanism at pH 5.5, 7.0, and 8.5. MRJP1 exhibited a higher binding affinity for Q at pH 8.5 and 7.0 than at pH 5.5. Hydrophilic interaction was the main driving force for the formation of the MRJP1–Q complex at pH 5.5–8.5. Molecular modeling further revealed that Q preferred to interact with the central domain of MRJP1 across all tested pH conditions. Importantly, the formation of the MRJP1–Q complex increased the apparent solubility of Q and synergistically enhanced the ABTS<img><sup>+</sup> radical scavenging capacities of both components. These findings suggest that the MRJP1–Q complex represents a nutritionally valuable substance with potent antioxidant capabilities, holding promise for functional food and nutraceutical applications.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127435"},"PeriodicalIF":4.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940314","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 : 2026-01-03DOI: 10.1016/j.saa.2026.127437
Shengli Cao , Zhuang Miao , Wenzheng Ruan , Bing Yan , Yuanqiang Sun
Drug-induced liver injury (DILI) is a significant public health issue due to its unpredictability and potential severity. DILI primarily manifests as hepatic steatosis or phospholipidosis, accompanied with an elevated lipid droplets (LDs) number. Therefore, developing powerful polarity-responsive probes that target LDs is critical for elucidating the precise function of LDs in DILI. Common solvatochromic polarity-sensitive probes often show a significant blue shift in their emission wavelength as the polarity decreases, with some probes exhibiting a shift of over 100 nm, leading to low accuracy. This wide wavelength coverage required for fluorescence imaging limits their use in multicolor imaging and studies on organelle interactions. In this study, we designed and synthesized a small-molecule environment-sensitive anti-bluing fluorescent probe based on a BODIPY scaffold. This probe was used to investigate dynamic changes in lipid droplets in hepatocytes under a DILI model, thereby providing a foundation for further exploration of the pathophysiological mechanisms underlying DILI-related diseases.
{"title":"Toward anti-bluing shift: A rationally designed photo-induced electron transfer-based polarity responsive lipid droplets-targeting fluorescent probe for real-time monitoring of drug-induced liver injury","authors":"Shengli Cao , Zhuang Miao , Wenzheng Ruan , Bing Yan , Yuanqiang Sun","doi":"10.1016/j.saa.2026.127437","DOIUrl":"10.1016/j.saa.2026.127437","url":null,"abstract":"<div><div>Drug-induced liver injury (DILI) is a significant public health issue due to its unpredictability and potential severity. DILI primarily manifests as hepatic steatosis or phospholipidosis, accompanied with an elevated lipid droplets (LDs) number. Therefore, developing powerful polarity-responsive probes that target LDs is critical for elucidating the precise function of LDs in DILI. Common solvatochromic polarity-sensitive probes often show a significant blue shift in their emission wavelength as the polarity decreases, with some probes exhibiting a shift of over 100 nm, leading to low accuracy. This wide wavelength coverage required for fluorescence imaging limits their use in multicolor imaging and studies on organelle interactions. In this study, we designed and synthesized a small-molecule environment-sensitive anti-bluing fluorescent probe based on a BODIPY scaffold. This probe was used to investigate dynamic changes in lipid droplets in hepatocytes under a DILI model, thereby providing a foundation for further exploration of the pathophysiological mechanisms underlying DILI-related diseases.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127437"},"PeriodicalIF":4.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940403","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 : 2026-01-03DOI: 10.1016/j.saa.2026.127436
Kang Yao , Shiquan Liu
This study investigated the impact of ZnO addition (0–5 wt%) on the structure, optical properties, and chemical stability of a neutral borosilicate glass with a nominal composition of 75SiO2-7Na2O-11.5B2O3–4.5Al2O3–0.6CaO-1K2O-0.4CeO2 (wt%), designed for pharmaceutical packaging. Comprehensive structural analyses (FTIR, Raman, 29Si/11B/27Al MAS NMR) and physical property measurement results (Density and molar volume, CTE and Vickers hardness) revealed that initial addition of ZnO by 1 wt% resulted in the formation of diborate groups and a large increase of viscosity from Z0 to Z1. With further increases of ZnO, it mainly acted as a network modifier depolymerizing the silicate network but increasing the network connectivity due to the formation of the reedmergnerite groups. This opposite effect as well as the large polarizability of interstitial Zn2+ well explained the smaller increase of viscosity for samples Z1 to Z5. In all cases, Al3+ existed in the form of [AlO4]. The variations of Q4(1Al) and CTE are closely dependent on the contents of Al2O3 in the prepared glasses, rather than on the content of ZnO. It was also found that the incorporation of ZnO enhanced the UV absorption of the glasses. However, it degraded the hydrolytic resistance of the glass. These opposite effects of ZnO highlighted the need to carefully weigh the benefits and drawbacks of ZnO addition in pharmaceutical glass formulations.
本研究考察了ZnO添加量（0-5 wt%）对中性硼硅酸盐玻璃（标称成分为75sio2 - 7na2o -11.5 b2o3 -4.5 al2o3 -0.6 cao - 1k20 -0.4 ceo2 (wt%)）结构、光学性能和化学稳定性的影响。综合结构分析（FTIR, Raman, 29Si/11B/27Al MAS NMR）和物理性能测量结果（密度和摩尔体积，CTE和维氏硬度）表明，初始添加1wt %的ZnO导致二硼酸盐基团的形成，并且粘度从Z0大幅增加到Z1。随着氧化锌含量的进一步增加，氧化锌主要作为网络调节剂使硅酸盐网络解聚，但由于芦苇美沙石基团的形成而增加了网络的连通性。这种相反的效应以及间隙Zn2+的大极化率很好地解释了样品Z1到Z5粘度增加较小的原因。在所有情况下，Al3+都以[AlO4]的形式存在。Q4（1Al）和CTE的变化与制备的玻璃中Al2O3的含量密切相关，而与ZnO的含量无关。氧化锌的掺入增强了玻璃对紫外线的吸收。然而，它降低了玻璃的抗水解性。氧化锌的这些相反作用突出了需要仔细权衡在药用玻璃配方中添加氧化锌的利弊。
{"title":"Effect of ZnO on the UV-shielding and hydrolytic resistance of neutral borosilicate glass","authors":"Kang Yao , Shiquan Liu","doi":"10.1016/j.saa.2026.127436","DOIUrl":"10.1016/j.saa.2026.127436","url":null,"abstract":"<div><div>This study investigated the impact of ZnO addition (0–5 wt%) on the structure, optical properties, and chemical stability of a neutral borosilicate glass with a nominal composition of 75SiO<sub>2</sub>-7Na<sub>2</sub>O-11.5B<sub>2</sub>O<sub>3</sub>–4.5Al<sub>2</sub>O<sub>3</sub>–0.6CaO-1K<sub>2</sub>O-0.4CeO<sub>2</sub> (wt%), designed for pharmaceutical packaging. Comprehensive structural analyses (FTIR, Raman, <sup>29</sup>Si/<sup>11</sup>B/<sup>27</sup>Al MAS NMR) and physical property measurement results (Density and molar volume, CTE and Vickers hardness) revealed that initial addition of ZnO by 1 wt% resulted in the formation of diborate groups and a large increase of viscosity from Z0 to Z1. With further increases of ZnO, it mainly acted as a network modifier depolymerizing the silicate network but increasing the network connectivity due to the formation of the reedmergnerite groups. This opposite effect as well as the large polarizability of interstitial Zn<sup>2+</sup> well explained the smaller increase of viscosity for samples Z1 to Z5. In all cases, Al<sup>3+</sup> existed in the form of [AlO<sub>4</sub>]. The variations of Q<sup>4</sup>(1Al) and CTE are closely dependent on the contents of Al<sub>2</sub>O<sub>3</sub> in the prepared glasses, rather than on the content of ZnO. It was also found that the incorporation of ZnO enhanced the UV absorption of the glasses. However, it degraded the hydrolytic resistance of the glass. These opposite effects of ZnO highlighted the need to carefully weigh the benefits and drawbacks of ZnO addition in pharmaceutical glass formulations.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127436"},"PeriodicalIF":4.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145919234","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 : 2026-01-03DOI: 10.1016/j.saa.2026.127434
Feng Li , Lu Zhang , Dong-Fang Gao , Yu-Jie Cao , Bao-Xiang Zhao , Zhao-Min Lin
In this work, a novel fluorescent probe (CBT) was developed by constructing an efficient fluorescence resonance energy transfer (FRET) and twisted intramolecular charge transfer (TICT) platform to identify SO2 and viscosity changes. CBT has excellent water solubility and exhibits superior fluorescence response performance without the involvement of organic solvents. The energy transfer efficiency (ETE) of CBT is quite high (99.2 %). Besides, CBT not only exhibits high selectivity (fluorescence intensity ratio enhanced 150-fold) and sensitivity (limit of detection: 24 nM) toward SO2 derivatives within 5 min, but also can detect sulfur dioxide derivatives in high-viscosity systems. CBT is highly sensitive to changes in viscosity, showing a significant increase in fluorescence, with the fluorescence intensity increasing by up to 113 times. Furthermore, CBT exhibits low toxicity and good photostability in cells, and can be used to monitor the changes of endogenous and exogenous SO2 derivatives in different living cells.
{"title":"An efficient dual-channel fluorescence probe for the detection of sulfur dioxide derivatives and viscosity","authors":"Feng Li , Lu Zhang , Dong-Fang Gao , Yu-Jie Cao , Bao-Xiang Zhao , Zhao-Min Lin","doi":"10.1016/j.saa.2026.127434","DOIUrl":"10.1016/j.saa.2026.127434","url":null,"abstract":"<div><div>In this work, a novel fluorescent probe (<strong>CBT</strong>) was developed by constructing an efficient fluorescence resonance energy transfer (FRET) and twisted intramolecular charge transfer (TICT) platform to identify SO<sub>2</sub> and viscosity changes. <strong>CBT</strong> has excellent water solubility and exhibits superior fluorescence response performance without the involvement of organic solvents. The energy transfer efficiency (ETE) of <strong>CBT</strong> is quite high (99.2 %). Besides, <strong>CBT</strong> not only exhibits high selectivity (fluorescence intensity ratio enhanced 150-fold) and sensitivity (limit of detection: 24 nM) toward SO<sub>2</sub> derivatives within 5 min, but also can detect sulfur dioxide derivatives in high-viscosity systems. <strong>CBT</strong> is highly sensitive to changes in viscosity, showing a significant increase in fluorescence, with the fluorescence intensity increasing by up to 113 times. Furthermore, <strong>CBT</strong> exhibits low toxicity and good photostability in cells, and can be used to monitor the changes of endogenous and exogenous SO<sub>2</sub> derivatives in different living cells.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127434"},"PeriodicalIF":4.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145919207","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 : 2026-01-03DOI: 10.1016/j.saa.2026.127441
Shuling Meng , Jianing Huang , Xiaoge Duan , Yaxiang Luo , Jiakang He , Hao Peng , Jun Li , Hailan Chen
Rotavirus (RV) infection is a zoonotic disease that primarily affects infants, young children, and young animals, with clinical manifestations including anorexia, vomiting, diarrhea, and dehydration. RV can be classified into seven groups (A–G), among which group A rotavirus (RVA) is the most prevalent and pathogenic. The high morbidity and mortality associated with RVA infection not only cause substantial economic losses to the livestock industry but also pose a serious threat to human health. Currently, the detection of RVA mainly relies on enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). However, these methods are limited by their complex procedures, long processing times, and high costs, making them unsuitable for rapid on-site diagnosis. In this study, a surface-enhanced Raman scattering-based lateral flow immunochromatographic assay (SERS-LFIA) employing gold nanostars (AuNS) as signal labels was developed for the rapid and sensitive detection of animal-derived RVA. AuNS were synthesized via a gold seed-mediated growth method. Mouse anti-RVA monoclonal antibodies and 5, 5’-Dithiobis (2-nitrobenzoic acid) (DTNB) were conjugated to the surface of AuNS through AuS bonds to prepare SERS immunoprobes, which were then deposited onto the conjugate pad during test strip assembly. The unique star-shaped morphology of AuNS significantly enhanced the analytical signals, achieving a visual limit of detection (LOD) of 1.02 × 103 copies/μL and a Raman signal-based LOD as low as 3.73 × 102 copies/μL. The method exhibited no cross-reactivity with other diarrhea-causing viruses or bacteria and showed an overall concordance rate of 95% (76/80) with RT-PCR when tested using 80 clinical samples. Furthermore, the RVA detection could be completed within 20 min without the need for complex instrumentation. Thus, the dual-signal-mode immunochromatographic assay demonstrates high sensitivity, specificity, and accuracy, making it highly suitable for the rapid on-site detection of RVA.
{"title":"Gold nanostars-based SERS-LFIA for the rapid and sensitive detection of group A rotavirus","authors":"Shuling Meng , Jianing Huang , Xiaoge Duan , Yaxiang Luo , Jiakang He , Hao Peng , Jun Li , Hailan Chen","doi":"10.1016/j.saa.2026.127441","DOIUrl":"10.1016/j.saa.2026.127441","url":null,"abstract":"<div><div>Rotavirus (RV) infection is a zoonotic disease that primarily affects infants, young children, and young animals, with clinical manifestations including anorexia, vomiting, diarrhea, and dehydration. RV can be classified into seven groups (A–G), among which group A rotavirus (RVA) is the most prevalent and pathogenic. The high morbidity and mortality associated with RVA infection not only cause substantial economic losses to the livestock industry but also pose a serious threat to human health. Currently, the detection of RVA mainly relies on enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). However, these methods are limited by their complex procedures, long processing times, and high costs, making them unsuitable for rapid on-site diagnosis. In this study, a surface-enhanced Raman scattering-based lateral flow immunochromatographic assay (SERS-LFIA) employing gold nanostars (AuNS) as signal labels was developed for the rapid and sensitive detection of animal-derived RVA. AuNS were synthesized via a gold seed-mediated growth method. Mouse anti-RVA monoclonal antibodies and 5, 5’-Dithiobis (2-nitrobenzoic acid) (DTNB) were conjugated to the surface of AuNS through Au<img>S bonds to prepare SERS immunoprobes, which were then deposited onto the conjugate pad during test strip assembly. The unique star-shaped morphology of AuNS significantly enhanced the analytical signals, achieving a visual limit of detection (LOD) of 1.02 × 10<sup>3</sup> copies/μL and a Raman signal-based LOD as low as 3.73 × 10<sup>2</sup> copies/μL. The method exhibited no cross-reactivity with other diarrhea-causing viruses or bacteria and showed an overall concordance rate of 95% (76/80) with RT-PCR when tested using 80 clinical samples. Furthermore, the RVA detection could be completed within 20 min without the need for complex instrumentation. Thus, the dual-signal-mode immunochromatographic assay demonstrates high sensitivity, specificity, and accuracy, making it highly suitable for the rapid on-site detection of RVA.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127441"},"PeriodicalIF":4.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145919153","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 : 2026-01-03DOI: 10.1016/j.saa.2026.127439
Ya Yun Lei, Xiao Yang, Yi Nuo Wang, Qi Tong Fu, Zhi Cheng Chen, Hong Qun Luo, Nian Bing Li
High-sensitivity circulating tumor DNA (ctDNA) detection technology is critical for early cancer diagnosis and treatment. However, the extremely low abundance of ctDNA in bodily fluids, coupled with various interfering factors, makes its effective detection particularly challenging. Herein, a label-free fluorescence sensor for ultrasensitive ctDNA detection was developed by integrating enzyme-assisted dual-DNA-loop amplification with a hybridization chain reaction (HCR). The target ctDNA binds to a hairpin probe, initiating a catalytic hairpin assembly cycle that forms a complex containing recognition sites for the endonuclease Nb.BbvCI. Upon binding its recognition site, Nb.BbvCI cooperates with KF polymerase to induce strand displacement amplification (SDA), forming a dual-cycle amplification process that generates an HCR trigger probe to initiate HCR and produce abundant complementary DNA sequences with multiple C-myc repeats. In the presence of Mg2+, these sequences fold into G-quadruplex structures. Subsequent intercalation of thioflavin T results in a dramatic enhancement of the fluorescence signal, enabling quantitative detection of ctDNA. The sensor demonstrates a linear response to ctDNA concentrations ranging from 10 fM to 1 nM, with a detection limit as low as 2.48 aM. This highly sensitive detection strategy offers promising potential for advancing early cancer diagnosis and personalized treatment.
{"title":"A label-free fluorescent biosensor leveraging cascaded DNA dual-cycle amplification and HCR for ultrasensitive detection of circulating tumor DNA","authors":"Ya Yun Lei, Xiao Yang, Yi Nuo Wang, Qi Tong Fu, Zhi Cheng Chen, Hong Qun Luo, Nian Bing Li","doi":"10.1016/j.saa.2026.127439","DOIUrl":"10.1016/j.saa.2026.127439","url":null,"abstract":"<div><div>High-sensitivity circulating tumor DNA (ctDNA) detection technology is critical for early cancer diagnosis and treatment. However, the extremely low abundance of ctDNA in bodily fluids, coupled with various interfering factors, makes its effective detection particularly challenging. Herein, a label-free fluorescence sensor for ultrasensitive ctDNA detection was developed by integrating enzyme-assisted dual-DNA-loop amplification with a hybridization chain reaction (HCR). The target ctDNA binds to a hairpin probe, initiating a catalytic hairpin assembly cycle that forms a complex containing recognition sites for the endonuclease Nb.<em>Bbv</em>CI. Upon binding its recognition site, Nb.BbvCI cooperates with KF polymerase to induce strand displacement amplification (SDA), forming a dual-cycle amplification process that generates an HCR trigger probe to initiate HCR and produce abundant complementary DNA sequences with multiple C-myc repeats. In the presence of Mg<sup>2+</sup>, these sequences fold into G-quadruplex structures. Subsequent intercalation of thioflavin T results in a dramatic enhancement of the fluorescence signal, enabling quantitative detection of ctDNA. The sensor demonstrates a linear response to ctDNA concentrations ranging from 10 fM to 1 nM, with a detection limit as low as 2.48 aM. This highly sensitive detection strategy offers promising potential for advancing early cancer diagnosis and personalized treatment.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127439"},"PeriodicalIF":4.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940376","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}
Intracellular viscosity serves as a biomarker for various diseases, as it is linked to multiple biological processes. Measuring intracellular viscosity precisely is essential for disease diagnosis and evaluating treatment efficacy. To address this, a viscosity-responsive, deep-red-emitting fluorescent probe (T5) has been synthesized using thiazolidinone and dimethylaminocinnamaldehyde as the acceptor and donor, respectively. The probe exhibits a “turn on” fluorescence response with high selectivity in highly viscous medium. The emission intensity of the probe at 641 nm increases progressively with increasing solvent viscosity. The working mechanism of the developed probe is primarily based on the restriction of intramolecular rotation (RIR) in a highly viscous medium, as further supported by DFT and TD-DFT analyses. The probe exhibits long-wavelength emission, which is advantageous for achieving deeper tissue penetration and higher sensitivity in bio-imaging applications. The practical applicability of the probe was evaluated by monitoring micro-environmental viscosity variations in a cell-based model comprising normal, cancerous and apoptotic MDA-MB-231 cells. Furthermore, the interaction of the probe with Bovine serum albumin (BSA) was investigated using UV–vis and fluorescence spectroscopy. Experimental results revealed that the probe binds within the hydrophobic cavity of BSA, a finding corroborated by molecular docking and dynamics studies. Overall, the developed sensor demonstrates strong potential not only as a sensitive detector of microenvironment viscosity in biological systems but also as a valuable tool for monitoring conformational changes in protein structures.
{"title":"Viscosity-sensitive NIR probe for detecting cellular state transitions in Normal, Cancer and apoptotic cells","authors":"Kiran , Anju Ranolia , Priyanka , Laxmi Narayan , Hussein Elrewey , Muhammad Wahajuddin , Parvin Kumar , Devender Singh , Gaurav Joshi , Jayant Sindhu","doi":"10.1016/j.saa.2026.127430","DOIUrl":"10.1016/j.saa.2026.127430","url":null,"abstract":"<div><div>Intracellular viscosity serves as a biomarker for various diseases, as it is linked to multiple biological processes. Measuring intracellular viscosity precisely is essential for disease diagnosis and evaluating treatment efficacy. To address this, a viscosity-responsive, deep-red-emitting fluorescent probe (<strong>T5</strong>) has been synthesized using thiazolidinone and dimethylaminocinnamaldehyde as the acceptor and donor, respectively. The probe exhibits a “<em>turn on</em>” fluorescence response with high selectivity in highly viscous medium. The emission intensity of the probe at 641 nm increases progressively with increasing solvent viscosity. The working mechanism of the developed probe is primarily based on the restriction of intramolecular rotation (RIR) in a highly viscous medium, as further supported by DFT and TD-DFT analyses. The probe exhibits long-wavelength emission, which is advantageous for achieving deeper tissue penetration and higher sensitivity in bio-imaging applications. The practical applicability of the probe was evaluated by monitoring micro-environmental viscosity variations in a cell-based model comprising normal, cancerous and apoptotic MDA-MB-231 cells. Furthermore, the interaction of the probe with Bovine serum albumin (BSA) was investigated using UV–vis and fluorescence spectroscopy. Experimental results revealed that the probe binds within the hydrophobic cavity of BSA, a finding corroborated by molecular docking and dynamics studies. Overall, the developed sensor demonstrates strong potential not only as a sensitive detector of microenvironment viscosity in biological systems but also as a valuable tool for monitoring conformational changes in protein structures.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127430"},"PeriodicalIF":4.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940373","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 : 2026-01-02DOI: 10.1016/j.saa.2025.127429
Xinwei Liu , Jiaqi Song , Meiheng Lv , Xintian Liu , Hongyang Liu , Wenze Li
Excited-state intramolecular proton transfer (ESIPT) has garnered significant attention in fluorescent sensors due to its unique photobiological and photochemical properties. In this work, the ESIPT behavior of a newly developed ESIPT-based fluorescent sensor (PYDP) under solvent polarity modulation has been systematically investigated. Bond parameters, infrared vibrational frequency analysis, nuclear valence branching index (CVB), and bond critical point (BCP) parameters indicate enhanced hydrogen bonding in the first excited state with solvent dependence. By investigating reaction energy barriers, it was elucidated that a reduction in solvent polarity favors the occurrence of the ESIPT reaction in PYDP molecules. Our findings hold significant implications for understanding solvent-polarity-regulated ESIPT characteristics, providing theoretical guidance for designing novel luminescent materials.
{"title":"Solvent-controlled excited-state intramolecular proton transfer in 4-methoxy tetramic acid derivative","authors":"Xinwei Liu , Jiaqi Song , Meiheng Lv , Xintian Liu , Hongyang Liu , Wenze Li","doi":"10.1016/j.saa.2025.127429","DOIUrl":"10.1016/j.saa.2025.127429","url":null,"abstract":"<div><div>Excited-state intramolecular proton transfer (ESIPT) has garnered significant attention in fluorescent sensors due to its unique photobiological and photochemical properties. In this work, the ESIPT behavior of a newly developed ESIPT-based fluorescent sensor (PYDP) under solvent polarity modulation has been systematically investigated. Bond parameters, infrared vibrational frequency analysis, nuclear valence branching index (CVB), and bond critical point (BCP) parameters indicate enhanced hydrogen bonding in the first excited state with solvent dependence. By investigating reaction energy barriers, it was elucidated that a reduction in solvent polarity favors the occurrence of the ESIPT reaction in PYDP molecules. Our findings hold significant implications for understanding solvent-polarity-regulated ESIPT characteristics, providing theoretical guidance for designing novel luminescent materials.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127429"},"PeriodicalIF":4.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145919454","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 : 2026-01-02DOI: 10.1016/j.saa.2025.127417
Yuxuan He , Jiayi Wei , Ming Cai , Junpeng Xia , Boheng Song , Jinxin Cheng , Xuanyu Sha
The performance of surface-enhanced Raman scattering (SERS) hinges on plasmonic hot spots that are both abundant and spatially uniform. Here, we propose a ligand-regulated, interface-confined growth strategy: on a bowl-like mesoporous polydopamine (PDA) scaffold, the ammoniacal silver precursor [Ag(NH3)2]+ first forms a surface coordination layer with catechol and amine sites on PDA, lowering the activity of free Ag+ and enriching Ag(I) at the interface, thereby shifting nucleation from homogeneous in the bulk to interface-confined. The ensuing constrained growth suppresses coalescence/bridging and excessive coarsening, yielding Ag nanoparticle arrays with controlled size, tunable interparticle gaps, and high spatial uniformity, and producing dense yet discrete coverage across both the inner and outer interfaces of the bowl. The concave curvature and dual-interface connectivity provide continuous coupling pathways and abundant adsorption sites, establishing a three-dimensional continuous hot-spot network. Correlative multi-technique characterization and spectroscopic analyses (SEM, EDS mapping, UV–Vis, XPS) elucidate the structure-optical-performance relationship, revealing a sparse-to-dense optimal regime and a coalescence-induced degradation regime, and identifying a precursor concentration of 50 mM as the optimal window. The resulting substrate exhibits good reproducibility for R6G (RSD ≈ 10.99 %) and affords clear molecular fingerprinting and linear quantification for pesticide analysis, with limits of detection of 55 ng mL−1 for methyl parathion and 0.209 ng mL−1 for thiram. This template-free, mild, and generalizable strategy provides a scalable route to three-dimensional plasmonic SERS substrates, leveraging PDA surface chemistry to prevent Ag aggregation at the source while constructing continuous hot spots networks.
表面增强拉曼散射（SERS）的性能取决于等离子体热点的丰富和空间均匀性。在这里，我们提出了一种配体调控的界面受限生长策略：在碗状介孔聚多巴胺（PDA）支架上，氨态银前体[Ag(NH3)2]+首先与PDA上的儿茶酚和胺位点形成表面配位层，降低游离Ag+的活性，并在界面处富集Ag(I)，从而将成核从整体均质转变为界面受限。随后的约束生长抑制了聚结/桥接和过度粗化，从而产生尺寸可控、颗粒间间隙可调、空间均匀性高的银纳米颗粒阵列，并在碗状结构的内外界面上产生密集而离散的覆盖。凹曲率和双界面连通性提供了连续的耦合途径和丰富的吸附位点，建立了三维连续的热点网络。相关的多技术表征和光谱分析（SEM, EDS mapping, UV-Vis， XPS）阐明了结构-光学-性能关系，揭示了从稀疏到密集的最佳机制和聚结诱导的降解机制，并确定了前驱体浓度为50 mM的最佳窗口。该底物对R6G具有良好的重现性（RSD≈10.99%），具有清晰的分子指纹图谱和线性定量，对甲基对硫磷的检出限为55 ng mL-1，对硫胺的检出限为0.209 ng mL-1。这种无模板、温和且可推广的策略为三维等离子体SERS衬底提供了可扩展的途径，利用PDA表面化学来防止银在源头聚集，同时构建连续的热点网络。
{"title":"PDA@ag Nanobowl SERS substrates with 3D continuous hot spots networks via an Interface-confined growth method for detection of pesticide residues","authors":"Yuxuan He , Jiayi Wei , Ming Cai , Junpeng Xia , Boheng Song , Jinxin Cheng , Xuanyu Sha","doi":"10.1016/j.saa.2025.127417","DOIUrl":"10.1016/j.saa.2025.127417","url":null,"abstract":"<div><div>The performance of surface-enhanced Raman scattering (SERS) hinges on plasmonic hot spots that are both abundant and spatially uniform. Here, we propose a ligand-regulated, interface-confined growth strategy: on a bowl-like mesoporous polydopamine (PDA) scaffold, the ammoniacal silver precursor [Ag(NH<sub>3</sub>)<sub>2</sub>]<sup>+</sup> first forms a surface coordination layer with catechol and amine sites on PDA, lowering the activity of free Ag<sup>+</sup> and enriching Ag(I) at the interface, thereby shifting nucleation from homogeneous in the bulk to interface-confined. The ensuing constrained growth suppresses coalescence/bridging and excessive coarsening, yielding Ag nanoparticle arrays with controlled size, tunable interparticle gaps, and high spatial uniformity, and producing dense yet discrete coverage across both the inner and outer interfaces of the bowl. The concave curvature and dual-interface connectivity provide continuous coupling pathways and abundant adsorption sites, establishing a three-dimensional continuous hot-spot network. Correlative multi-technique characterization and spectroscopic analyses (SEM, EDS mapping, UV–Vis, XPS) elucidate the structure-optical-performance relationship, revealing a sparse-to-dense optimal regime and a coalescence-induced degradation regime, and identifying a precursor concentration of 50 mM as the optimal window. The resulting substrate exhibits good reproducibility for R6G (RSD ≈ 10.99 %) and affords clear molecular fingerprinting and linear quantification for pesticide analysis, with limits of detection of 55 ng mL<sup>−1</sup> for methyl parathion and 0.209 ng mL<sup>−1</sup> for thiram. This template-free, mild, and generalizable strategy provides a scalable route to three-dimensional plasmonic SERS substrates, leveraging PDA surface chemistry to prevent Ag aggregation at the source while constructing continuous hot spots networks.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127417"},"PeriodicalIF":4.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145936769","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 : 2026-01-02DOI: 10.1016/j.saa.2025.127425
Yuxiao Qin, Jiayi Liu, Caixia Lin, Yaofeng Yuan
A series of o-carborane-based aza-oxa-triazole macrocycles (No, D2, D4) were synthesized via Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC). Simply by substituting the azide diethanolamine precursor, two dansyl-modified macrocycles (D2 and D4) with dual-state emission (DSE) were readily obtained. The incorporation of the dansyl moiety significantly enhanced the luminescence, resulting in higher quantum yields and longer fluorescence lifetimes. Additionally, the macrocycles exhibit unique aggregation-induced emission (AIE) properties and macrocycles D2 and D4 simultaneously exhibit aggregation-induced quenching (ACQ) and AIE characteristics. Furthermore, these macrocycles function as selective fluorescent sensors for nitroaromatic compounds, particularly demonstrating excellent specificity and anti-interference ability toward 2,4,6-trinitrophenol (TNP) with a notable fluorescence quenching response. Macrocycle D2 achieved a remarkably low detection limit of 7 × 10−8 M for TNP in THF.
{"title":"Dual-state emissive carborane-based aza-oxa-triazole macrocycles as probes for nitroaromatic compounds","authors":"Yuxiao Qin, Jiayi Liu, Caixia Lin, Yaofeng Yuan","doi":"10.1016/j.saa.2025.127425","DOIUrl":"10.1016/j.saa.2025.127425","url":null,"abstract":"<div><div>A series of <em>o</em>-carborane-based aza-oxa-triazole macrocycles (<strong>No</strong>, <strong>D</strong><sub><strong>2</strong></sub>, <strong>D</strong><sub><strong>4</strong></sub><strong>)</strong> were synthesized via Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC). Simply by substituting the azide diethanolamine precursor, two dansyl-modified macrocycles (<strong>D</strong><sub><strong>2</strong></sub> and <strong>D</strong><sub><strong>4</strong></sub>) with dual-state emission (DSE) were readily obtained. The incorporation of the dansyl moiety significantly enhanced the luminescence, resulting in higher quantum yields and longer fluorescence lifetimes. Additionally, the macrocycles exhibit unique aggregation-induced emission (AIE) properties and macrocycles <strong>D</strong><sub><strong>2</strong></sub> and <strong>D</strong><sub><strong>4</strong></sub> simultaneously exhibit aggregation-induced quenching (ACQ) and AIE characteristics. Furthermore, these macrocycles function as selective fluorescent sensors for nitroaromatic compounds, particularly demonstrating excellent specificity and anti-interference ability toward 2,4,6-trinitrophenol (TNP) with a notable fluorescence quenching response. Macrocycle <strong>D</strong><sub><strong>2</strong></sub> achieved a remarkably low detection limit of 7 × 10<sup>−8</sup> M for TNP in THF.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127425"},"PeriodicalIF":4.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145919188","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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