Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy最新文献_第2页

Evaluating the global cellular pharmacological effects of photodynamic therapy using label-free surface-enhanced Raman spectroscopy. 利用无标记表面增强拉曼光谱评估光动力疗法的整体细胞药理作用。

IF 4.6

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Pub Date : 2026-12-05 Epub Date: 2026-06-07 DOI: 10.1016/j.saa.2026.128215

Qingxia Zhu, Qing Zhou, Shiwei Wang, Yongfang Yuan, Feng Lu

{"title":"Evaluating the global cellular pharmacological effects of photodynamic therapy using label-free surface-enhanced Raman spectroscopy.","authors":"Qingxia Zhu, Qing Zhou, Shiwei Wang, Yongfang Yuan, Feng Lu","doi":"10.1016/j.saa.2026.128215","DOIUrl":"10.1016/j.saa.2026.128215","url":null,"abstract":"Photodynamic therapy (PDT) has attracted widespread attention as an emerging cancer treatment, yet real-time monitoring of tumor oxidative stress during therapy remains challenging due to unclear mechanistic insights, delayed efficacy evaluation, and inefficient drug screening. This study employed label-free dynamic surface-enhanced Raman spectroscopy (D-SERS) to evaluate the cellular pharmacological effects of PDT, enabling the mechanism-based classification of agents. Label-free D-SERS was used to monitor real-time spectral changes in human melanoma cells during PDT, characterizing the differences between apoptosis-inducing (type A) and necrosis-inducing (type B) photosensitizers. Type A exhibited concentration-dependent increases in Raman peaks at 652, 742, 828, and 1000 cm-1, a trend absent in Type B. By analyzing DNA, lipid, and amino acid peak ratios, cells treated with these photosensitizers were clearly classified into two mechanistic groups (A and B). Furthermore, D-SERS was applied to study the Type B agent 5-ALA in combination with heme oxygenase-1 (HO-1) modulators, verifying the associated enzyme-regulatory processes. This study presents a proof-of-concept model for the spectral mechanism-based screening of photosensitizers and enzyme modulators, thus aiding the optimization of PDT efficacy and targeted drug development.","PeriodicalId":94213,"journal":{"name":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","volume":"362 ","pages":"128215"},"PeriodicalIF":4.6,"publicationDate":"2026-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148274187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Intelligent SERS sensing strategy based on Ag NP fractal networks and gradient kernel size CNN for high-precision sweat monitoring. 基于Ag NP分形网络和梯度核尺寸CNN的高精度汗液监测智能SERS传感策略

IF 4.6

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Pub Date : 2026-12-05 Epub Date: 2026-06-12 DOI: 10.1016/j.saa.2026.128244

Xin Li, Xinghua Yang, Rui Wang, Pingping Teng, Shuai Gao, Nan Lu, Xiaoyu Li, Adam Jones, Kang Li

{"title":"Intelligent SERS sensing strategy based on Ag NP fractal networks and gradient kernel size CNN for high-precision sweat monitoring.","authors":"Xin Li, Xinghua Yang, Rui Wang, Pingping Teng, Shuai Gao, Nan Lu, Xiaoyu Li, Adam Jones, Kang Li","doi":"10.1016/j.saa.2026.128244","DOIUrl":"10.1016/j.saa.2026.128244","url":null,"abstract":"Surface-enhanced Raman scattering (SERS) is a promising tool for sweat analysis, but signal noise, nonlinear responses, and spectral overlap limit its quantitative accuracy in complex samples. In this work, an intelligent SERS sensing strategy was developed by combining an Ag NP fractal substrate with a Gradient Kernel Size Convolutional Neural Network (GKS-CNN). The self-assembled Ag NP substrate provided abundant electromagnetic hotspots, enabling sensitive detection of lactate (LA) and glucose (Glu) from 10-4 to 101 mM, with limits of detection of 108 nM and 224 nM, respectively. PCA results showed that the preprocessed SERS spectra contained distinguishable concentration-related information. Compared with linear regression, traditional machine learning methods, and standard CNNs, GKS-CNN achieved better prediction performance by extracting multi-scale features from nonlinear and overlapping spectra. For pure-component samples, the R2 values of LA and Glu reached 0.99 and 0.98, respectively; for the joint dataset containing pure and mixed samples, the R2 values were 0.98 and 0.97, respectively. In real sweat analysis, sample-level splitting was used to reduce data leakage, and the model classified four exercise-related states with an independent test accuracy of 95.00%. The average accuracies of 20 repeated random splits and 5-fold cross-validation were 94.50% and 93.50%, respectively. These results suggest that the proposed SERS-GKS-CNN strategy has potential for non-invasive sweat metabolite analysis and preliminary physiological-state recognition.","PeriodicalId":94213,"journal":{"name":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","volume":"362 ","pages":"128244"},"PeriodicalIF":4.6,"publicationDate":"2026-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148261271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced and tunable white luminescence in NaGdGeO₄: Bi³⁺, Dy³⁺ phosphors featuring anomalous thermal quenching. 异常热猝灭的NaGdGeO₄：Bi3+， Dy3+荧光粉中增强和可调谐的白光。

IF 4.6

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Pub Date : 2026-12-05 Epub Date: 2026-06-13 DOI: 10.1016/j.saa.2026.128251

Xihu Wang, Tianwei Jin, Zhi Lu, Jingwen Zhou, Wenjie Tian, Jun Li, Jinyu Hu

{"title":"Enhanced and tunable white luminescence in NaGdGeO₄: Bi3+, Dy3+ phosphors featuring anomalous thermal quenching.","authors":"Xihu Wang, Tianwei Jin, Zhi Lu, Jingwen Zhou, Wenjie Tian, Jun Li, Jinyu Hu","doi":"10.1016/j.saa.2026.128251","DOIUrl":"10.1016/j.saa.2026.128251","url":null,"abstract":"A novel series of NaGdGeO₄ phosphors co-doped with Bi3+ and Dy3+ ions were successfully synthesized via a conventional high-temperature solid-state reaction method. By systematically varying the Dy3+/Bi3+ doping concentrations, the emission color under 347 nm excitation could be effectively tuned from blue to cool white. Remarkably, these phosphors exhibit a distinct anomalous thermal quenching behavior. Specifically, for the NGGO: 0.01Bi3+, 0.05Dy3+ phosphor, the luminescence intensity at 577 nm measured at 573 K reached 163.2% of its initial value at 293 K, demonstrating exceptional thermal stability for high-temperature applications. The energy transfer process from Bi3+ to Dy3+ was comprehensively investigated through photoluminescence spectroscopy and decay lifetime measurements. This anomalous thermal quenching phenomenon is attributed to the synergistic effect of temperature-dependent modulation of the energy transfer efficiency from Bi3+ (3P1 → 1S0) to Dy3+ (4F9/2 → 6H13/2) and the direct excitation of Dy3+ at 347 nm. This work highlights the significant potential of NaGdGeO₄: Bi3+, Dy3+ phosphors for application in white light-emitting diodes, particularly where thermal management is critical.","PeriodicalId":94213,"journal":{"name":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","volume":"362 ","pages":"128251"},"PeriodicalIF":4.6,"publicationDate":"2026-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148267530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cell-in-water: complementary optical photothermal infrared and Raman microscopy for submicron chemical imaging of hydrated cells. 水中细胞：互补光学光热红外和拉曼显微镜用于水合细胞的亚微米化学成像。

IF 4.6

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Pub Date : 2026-12-05 Epub Date: 2026-06-12 DOI: 10.1016/j.saa.2026.128241

Wiktoria Korona, Anna M Nowakowska, Anna Pieczara, Barbara Orzechowska, Miriam Unger, Malgorzata Baranska

{"title":"Cell-in-water: complementary optical photothermal infrared and Raman microscopy for submicron chemical imaging of hydrated cells.","authors":"Wiktoria Korona, Anna M Nowakowska, Anna Pieczara, Barbara Orzechowska, Miriam Unger, Malgorzata Baranska","doi":"10.1016/j.saa.2026.128241","DOIUrl":"10.1016/j.saa.2026.128241","url":null,"abstract":"Conventional Fourier transform infrared absorption spectroscopy is constrained by diffraction-limited spatial resolution and overwhelming absorption of water, typically requiring sample dehydration, which disrupts native cellular morphology. While Optical Photothermal Infrared microscopy overcomes the resolution barrier, reliable imaging of cells in their native, hydrated state remains a significant methodological challenge. In this work, an optimized Cell-in-Water protocol is presented for submicron, label-free chemical imaging of hydrated cells. The implementation of a silicone-sealed microchamber ensures a stable aqueous environment, preventing evaporation and enabling stable imaging for up to 4 h. Using a robust ratiometric data analysis framework, subcellular organelles, including nuclei and lipid droplets, are visualized with a lateral resolution of 300-500 nm. The protocol's reliability was validated through a comparative study of individual cells in both hydrated and dehydrated states, revealing critical spectral shifts and morphological distortions inherently associated with the drying process. These results provide a standardized, reproducible workflow for non-invasive, high-resolution biochemical mapping in aqueous environments, bridging the gap between conventional vibrational spectroscopy and the requirements of advanced biological imaging.","PeriodicalId":94213,"journal":{"name":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","volume":"362 ","pages":"128241"},"PeriodicalIF":4.6,"publicationDate":"2026-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148274222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Integrating CO₂ laser photoacoustic spectroscopy with explainable CNNs for post-harvest quality assessment of Diospyros kaki. co2激光光声光谱与可解释cnn相结合用于红木采后品质评价。

IF 4.6

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Pub Date : 2026-12-05 Epub Date: 2026-06-14 DOI: 10.1016/j.saa.2026.128257

Cristina Popa, Mioara Petrus, Ana-Maria Bratu, Leonard Gebac, Vasile Bercu

{"title":"Integrating CO₂ laser photoacoustic spectroscopy with explainable CNNs for post-harvest quality assessment of Diospyros kaki.","authors":"Cristina Popa, Mioara Petrus, Ana-Maria Bratu, Leonard Gebac, Vasile Bercu","doi":"10.1016/j.saa.2026.128257","DOIUrl":"10.1016/j.saa.2026.128257","url":null,"abstract":"This study presents a non-invasive molecular spectroscopy approach for monitoring storage-related physiological changes in Diospyros kaki (Hachiya persimmon). CO₂ laser photoacoustic spectroscopy (CO₂LPAS) was applied to quantify ethylene, ethanol, and ammonia emissions from individual fruits over a six-week storage period. Early ethylene release triggered ripening processes, followed by ethanol accumulation indicative of low-oxygen metabolism and microbial activity. Progressive ammonia emissions reflected proteolytic activity and tissue degradation during late-stage spoilage. To correlate internal metabolic signatures with external phenotypic changes, visual inspection was combined with high-resolution RGB imaging and a convolutional neural network (CNN) classification into three physiological macro-states: Storage, Transition, and Spoilage. The CNN was trained using 5-fold stratified cross-validation with test-time augmentation, achieving a mean classification accuracy of 91.67 ± 3.73%. Gradient-weighted Class Activation Mapping (Grad-CAM) highlighted regions contributing to classification, showing a shift from specular highlights in early stages to tissue deformation and necrosis in later stages, confirming the link between molecular emissions and structural degradation. The combined use of CO₂LPAS-based molecular spectroscopy and image-based assessment provides a complementary framework for real-time, non-invasive evaluation of storage-related fruit quality. These results demonstrate that ethylene, ethanol, and ammonia serve as robust molecular markers of ripening, anaerobic metabolism, and spoilage, while complementary imaging captures macroscopic deterioration. This dual-method framework offers potential for predictive postharvest monitoring, quality control, and shelf-life assessment of climacteric fruits.","PeriodicalId":94213,"journal":{"name":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","volume":"362 ","pages":"128257"},"PeriodicalIF":4.6,"publicationDate":"2026-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148274202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamic UV-Vis monitoring of ternary pharmaceutical photodegradation using multivariate curve resolution and predictive modeling. 基于多元曲线分辨率和预测模型的三元药物光降解动态紫外-可见监测。

IF 4.6

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Pub Date : 2026-10-20 DOI: 10.1016/j.saa.2026.129014

Daysi Elusaí Millán Ocampo, Susana Silva Martínez

{"title":"Dynamic UV-Vis monitoring of ternary pharmaceutical photodegradation using multivariate curve resolution and predictive modeling.","authors":"Daysi Elusaí Millán Ocampo, Susana Silva Martínez","doi":"10.1016/j.saa.2026.129014","DOIUrl":"https://doi.org/10.1016/j.saa.2026.129014","url":null,"abstract":"Ultraviolet (UV) photodegradation of multicomponent pharmaceutical systems generates complex spectral signals due to overlapping absorption bands and transient intermediates, limiting conventional quantitative approaches. To address this challenge, an integrated chemometric strategy was developed to predict concentration profiles in dynamic ternary mixtures of paracetamol (PAR), naproxen sodium (NPX), and diclofenac sodium (DIC) in spiked river water using Ultraviolet-visible (UV-Vis) spectroscopy. UV-Vis spectra from individual photolysis experiments were analyzed by Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) to estimate concentration profiles of the parent pharmaceuticals. These profiles were associated with ternary mixture spectra reconstructed by linear combination of the spectral data obtained from the individual photolysis experiments. The combined spectral data, together with experimentally acquired calibration data, served as input to develop a linear Partial Least Squares (PLS) and non-linear Artificial Neural Network (ANN) models, enabling simultaneous prediction of component concentrations. The degree of nonlinearity in the calibration datasets was first assessed using the Non-Linearity Degree (NLD), yielding values of 0.248, 0.398, and 0.214 for PAR, NPX, and DIC, respectively. These results exceeded the 0.05 threshold, indicating significant non-linear behavior in the calibration datasets. Accordingly, the linear PLS model showed limited predictive performance, particularly for DIC. In contrast, the non-linear ANN model achieved higher predictive accuracy, demonstrating its superior suitability for the dynamically evolving multicomponent systems.","PeriodicalId":94213,"journal":{"name":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","volume":"367 Pt 2","pages":"129014"},"PeriodicalIF":4.6,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149279188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Handheld spatially offset Raman spectroscopy for the simultaneous quantification of key quality parameters in cosmetic raw materials. 手持式空间偏移拉曼光谱用于化妆品原料中关键质量参数的同时定量。

IF 4.6

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Pub Date : 2026-10-17 DOI: 10.1016/j.saa.2026.129001

João Mário Morais Minetto, Leonardo Francisco Rafael Lemes, Frederico Luis Felipe Soares

{"title":"Handheld spatially offset Raman spectroscopy for the simultaneous quantification of key quality parameters in cosmetic raw materials.","authors":"João Mário Morais Minetto, Leonardo Francisco Rafael Lemes, Frederico Luis Felipe Soares","doi":"10.1016/j.saa.2026.129001","DOIUrl":"https://doi.org/10.1016/j.saa.2026.129001","url":null,"abstract":"Conventional titration methods used for quality control of cosmetic raw materials are time-consuming, labor-intensive, and require chemical reagents. This study developed a rapid and non-destructive approach based on handheld Spatially Offset Raman Spectroscopy (SORS) combined with chemometrics for the determination of iodine value (IV), saponification value (SV), and peroxide value (PV). A diverse dataset of 284 cosmetic raw materials, including oils, esters, butters, and waxes, was analyzed using a handheld Raman spectrometer. Optimization of the sampling strategy identified a low-density polyethylene (LDPE) support obtained from a Pasteur pipette as the most suitable configuration for SORS measurements, providing spectra comparable to those obtained by direct analysis while minimizing polymer interference and thermal effects. Raman spectra were preprocessed using asymmetric least squares (AsLS) and Savitzky-Golay derivatives and modeled using partial least squares (PLS) regression. The developed models showed coefficients of determination above 0.97 and RPD values above 3 for all evaluated parameters, demonstrating their suitability for approximate quantitative predictions. Permutation tests confirmed the statistical significance of the models, while elliptic joint confidence region analysis (EJCR) indicated the absence of systematic bias. Overall, the proposed approach provides a fast, reagent-free, and minimally invasive alternative to conventional titration methods, with strong potential for routine quality control of cosmetic raw materials.","PeriodicalId":94213,"journal":{"name":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","volume":"367 Pt 2","pages":"129001"},"PeriodicalIF":4.6,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Temperature dependence of complex permittivity of calcium sulfate dihydrate investigation by terahertz time-domain spectroscopy. 用太赫兹时域光谱研究二水合硫酸钙复介电常数的温度依赖性。

IF 4.6

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Pub Date : 2026-01-15 Epub Date: 2025-07-28 DOI: 10.1016/j.saa.2025.126744

Zhiyuan Zheng, Mingrui Zhang, Yibo Xu, Lixian Hao, Chutong Gao, Tong Zhang, Shanshan Li, Haochong Huang, Kunfeng Qiu, Yixing Geng, Yanying Zhao, Hao Liu

{"title":"Temperature dependence of complex permittivity of calcium sulfate dihydrate investigation by terahertz time-domain spectroscopy.","authors":"Zhiyuan Zheng, Mingrui Zhang, Yibo Xu, Lixian Hao, Chutong Gao, Tong Zhang, Shanshan Li, Haochong Huang, Kunfeng Qiu, Yixing Geng, Yanying Zhao, Hao Liu","doi":"10.1016/j.saa.2025.126744","DOIUrl":"10.1016/j.saa.2025.126744","url":null,"abstract":"As a common sulfate mineral on Martian surface, calcium sulfate hydrate experiences wide temperature variations. However, the permittivity properties of calcium sulfate hydrate as a function of temperature remains underexplored. In this study, this gap has been addressed by systematically investigating the complex permittivity of calcium sulfate dihydrate (CaSO4·2H2O) in THz frequency band using terahertz time-domain spectroscopy over a temperature range from 100 K to 320 K. Base on the effective medium theory of Landau-Lifshitz-Looyenga (LLL), the permittivity has been extracted from the matrix and compared with that of the calcium sulfate (CaSO4). It is found that as the temperature increases from 100 K to 320 K, the real part and the imaginary part of the permittivity for CaSO4·2H2O increases from 5.3 to 5.8, and 0.25 to 0.32 at 1.0 THz, respectively. For CaSO4, the corresponding values change from 5.2 to 5.3 and 0.28 to 0.4 respectively. The difference in the permittivity properties is mainly attributed to the temperature-dependent changes in crystal-water molecular polarizability, as well as its frequency-dependent response. Finally, to investigate the effect of solar-wind on these properties, calcium sulfate dihydrate irradiated by proton with a fluence of 2 × 1010 protons/cm2 has also been measured and discussed. Following proton irradiation, at 220 K the real part of the permittivity increases approximately 0.3, while the imaginary part of the permittivity decreases about 0.2. These findings provide valuable insights into the temperature-sensitive permittivity behavior of hydrated minerals as well as to quantitatively identify minerals on the Mars.","PeriodicalId":94213,"journal":{"name":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","volume":"345 ","pages":"126744"},"PeriodicalIF":4.6,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144805565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Detection of antibiotic-resistant Escherichia coli using surface-enhanced Raman spectroscopy and infrared spectroscopy. 表面增强拉曼光谱和红外光谱检测耐药大肠杆菌。

IF 4.6

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Pub Date : 2026-01-15 Epub Date: 2025-07-30 DOI: 10.1016/j.saa.2025.126759

Yanying Rao, Hong Li, Xiaoying Ding, Binggui Wang, Yuanli Liu, Xiaoxu Zhao

{"title":"Detection of antibiotic-resistant Escherichia coli using surface-enhanced Raman spectroscopy and infrared spectroscopy.","authors":"Yanying Rao, Hong Li, Xiaoying Ding, Binggui Wang, Yuanli Liu, Xiaoxu Zhao","doi":"10.1016/j.saa.2025.126759","DOIUrl":"10.1016/j.saa.2025.126759","url":null,"abstract":"In this study, Surface-enhanced Raman Spectroscopy (SERS) and Fourier Transform Infrared Spectroscopy (FTIR) were employed to investigate the molecular changes in Escherichia coli (E. coli) induced by exposure to ampicillin (AMP), enrofloxacin (ENR), ciprofloxacin (CIP), and norfloxacin (NFX) over time. The optimal concentration of E. coli for SERS analysis was determined to be 50 μL of bacterial suspension, diluted six times to achieve an OD600 ≈ 0.1. The primary changes in the SERS spectra were observed at 1267 cm-1, corresponding to the amide III band in proteins, while the FTIR spectra revealed significant changes in the 1200-900 cm-1 range, associated with carbohydrates, under AMP treatment. ENR, CIP, and NFX, which are quinolone antibiotics, act as inhibitors of DNA synthesis. The main changes in the SERS spectra for antibiotic-resistant E. coli were observed at 760 cm-1 (attributed to cytosine and uracil), 960 cm-1 (CN stretching and CC deformation), and 1140 cm-1 (COC stretching and ring breathing). In the FTIR spectra, significant changes were detected at 1655 cm-1, 1544 cm-1, and 1239 cm-1, corresponding to the amide I, amide II, and amide III bands, respectively. The combination of SERS and FTIR with principal component analysis (PCA) enabled the detection of molecular modifications in antibiotic-resistant E. coli exposed to different classes of antibiotics. These findings enhance our understanding of the mechanisms of action of antibiotics in bacteria.","PeriodicalId":94213,"journal":{"name":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","volume":"345 ","pages":"126759"},"PeriodicalIF":4.6,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144805558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of dielectric studies of paracetamol-diethylamine solutions: Experimental and machine learning approach. 对乙酰氨基酚-二乙胺溶液介电性研究：实验与机器学习方法。

IF 4.6

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Pub Date : 2026-01-15 Epub Date: 2025-08-05 DOI: 10.1016/j.saa.2025.126767

P M Prajapati, Sanketsinh Thakor, Prince Jain, V A Rana, T R Pandit

{"title":"Investigation of dielectric studies of paracetamol-diethylamine solutions: Experimental and machine learning approach.","authors":"P M Prajapati, Sanketsinh Thakor, Prince Jain, V A Rana, T R Pandit","doi":"10.1016/j.saa.2025.126767","DOIUrl":"10.1016/j.saa.2025.126767","url":null,"abstract":"This paper discusses about the dielectric studies of binary mixtures of paracetamol (PCM) and Diethylamine (DEA). Parallel resistance (Rp) and Parallel capacitance (Cp) measured using a precision LCR meter over a frequency range of 20 Hz-2 MHz at four distinct temperatures, starting from 293.15 K and increasing by 10 K for each subsequent measurement. These experimental parameters were used to compute the complex dielectric function, from which electrical properties like complex conductivity, complex impedance and complex electrical modulus-were derived. In addition to conventional analysis, machine learning (ML) models were implemented to predict dielectric constant (ε') and dielectric loss (ε″) values based experimental inputs, with their predictive performance significantly enhanced through Bayesian hyperparameter optimization. This dual approach of combining experimental data with ML modelling offers a novel methodology for efficient and accurate characterization of dielectric systems. The added value of this study lies in its ability to bridge physical measurements with computational predictions, reducing experimental workloads and improving generalization in similar systems. The findings have potential applications in material science, pharmaceuticals, and electronic device modelling. This study demonstrates that ML assisted dielectric analysis can serve as a powerful tool in predictive material characterization.","PeriodicalId":94213,"journal":{"name":"Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy","volume":"345 ","pages":"126767"},"PeriodicalIF":4.6,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144805562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0