Spectrochimica Acta. Part A, Molecular And Biomolecular Spectroscopy[JOURNAL]
Sun
200 papers
Evaluating the global cellular pharmacological effects of photodynamic therapy using label-free surface-enhanced Raman spectroscopy.
Zhu Q, Zhou Q, Wang S … +2 more , Yuan Y, Lu F
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42309032 · Publisher ↗
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, de...
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, 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.
Ultrasensitive SERS platform for cisplatin detection using self-assembled gold nanooctahedra-silver nanocube core-shell nanoparticles.
Cheng C, Pan W, Xing T … +6 more , Shen J, Dong Y, Xu Y, Zhao Y, Wang C, Sun W
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42309031 · Publisher ↗
This study addresses the critical need for rapid and sensitive detection of cisplatin, a widely used chemotherapeutic agent often limited by severe toxicities and drug resistance. Traditional detection methods are time-c...
This study addresses the critical need for rapid and sensitive detection of cisplatin, a widely used chemotherapeutic agent often limited by severe toxicities and drug resistance. Traditional detection methods are time-consuming and unsuitable for point-of-care applications. We developed an surface-enhanced Raman scattering (SERS) platform leveraging novel gold nanooctahedra‑silver nanocube core-shell (AuNO@AgNC) nanoparticles. Finite-difference time-domain (FDTD) simulations predicted a local field enhancement factor of 153.30 for the isolated nanostructure and further supported the use of 633 nm excitation by revealing a red-shifted coupled dimer plasmon mode near 644 nm in the film-relevant configuration. A facile oil-liquid interfacial self-assembly method enabled the fabrication of highly uniform SERS films. Evaluation with Rhodamine 6G (R6G) demonstrated a linear detection range from 0.5 nM to 500 nM, an impressive SERS enhancement factor of 1.57×10, and excellent signal reproducibility (relative standard deviation, RSD, of 14.85%). Applying this platform for cisplatin detection yielded a calibration range from 5 nM to 1000 nM, with an S/N-based limit of detection (LOD) of 1.9 nM and a limit of quantification (LOQ) of 6.5 nM. This research highlights the significant potential of our AuNO@AgNC SERS substrate for quantitative monitoring of low-concentration anticancer drugs.
Spectral fingerprints of picarbutrazox and its major hydrolysis products: A combined UV-vis, FTIR, Raman and DFT study.
Deng X, Sun Z, Chen J … +2 more , Lang J, Zhou W
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42309030 · Publisher ↗
The hydrolysis behavior of the fungicide picarbutrazox (PBZ) was investigated with an emphasis on the spectroscopic differentiation of its major transformation products. PBZ and three major hydrolysis products (HP1-HP3)...
The hydrolysis behavior of the fungicide picarbutrazox (PBZ) was investigated with an emphasis on the spectroscopic differentiation of its major transformation products. PBZ and three major hydrolysis products (HP1-HP3) were characterized experimentally using UV-vis, Fourier-transform infrared (FTIR), and surface-enhanced Raman scattering (SERS)/Raman spectroscopy, and the observed spectral features were interpreted with the aid of density functional theory (DFT) and time-dependent DFT (TDDFT) calculations. PBZ exhibits two distinct UV-vis absorption bands at 223 and 273 nm, whereas hydrolysis leads to pronounced spectral changes. HP1 shows a single dominant absorption band at approximately 224 nm, HP2 retains two absorption bands with a blue-shifted long-wavelength feature at around 262 nm, and HP3 displays absorption mainly in the deep-UV region (210-220 nm). FTIR spectra reveal systematic shifts in characteristic vibrational bands associated with carbonyl, CN, and ring skeletal vibrations, reflecting the structural reorganization induced by hydrolysis. In the SERS/Raman spectra, each compound presents a distinct fingerprint pattern, with HP1 exhibiting a prominent diagnostic Raman band at 1007 cm that is absent in PBZ. The calculated UV-vis, infrared, and conventional Raman spectra supported the assignment of major absorption and vibrational bands, whereas the Raman calculations were not intended to directly simulate SERS intensities. Theoretical analyses further indicate that hydrolysis induces redistribution of charge density and excitation localization, providing a molecular-level explanation for the observed spectral divergence. These results demonstrate that combined multi-spectroscopic measurements and quantum-chemical calculations enable reliable identification and differentiation of PBZ and its hydrolysis products, and provide practical spectral fingerprints for analytical identification of pesticide hydrolysis products. This work provides a PBZ-specific framework linking hydrolysis-product identification, multi-spectroscopic fingerprints, and molecular-level interpretation of hydrolysis-induced spectral changes.
Comparison FT-IR spectral fingerprints of kidney Cancer in urine and serum: Clinical correlations and diagnostic potential.
Mitura P, Odrzywolski A, Gumbarewicz E … +3 more , Godzisz M, Kuliniec I, Depciuch J
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42309029 · Publisher ↗
The identification of non-invasive biomarkers that not only detect kidney cancer but also reflect clinically relevant tumor characteristics remains a major challenge in translational oncology. In this study, we aimed to...
The identification of non-invasive biomarkers that not only detect kidney cancer but also reflect clinically relevant tumor characteristics remains a major challenge in translational oncology. In this study, we aimed to identify specific FT-IR spectral wavenumbers in two biofluids: serum and urine and to directly correlate these spectroscopic markers with established clinicopathological parameters, including histological grade and tumor characteristics. By linking molecular-level spectral information with medical data, we sought to determine whether biochemical alterations detected in biofluids truly mirror histopathological findings and tumor biology. Second-derivative FT-IR spectra were collected from serum and urine samples obtained from patients with renal tumors and healthy controls. Multivariate exploratory analyses (PCA, UMAP), stability-based feature selection, and supervised classification with leave-one-patient-out cross-validation were performed independently for both biofluids. The most discriminatory and stable wavenumbers were identified and subsequently evaluated for their association with clinical variables. Urine spectra demonstrated stronger class separation and higher classification accuracy compared with serum, achieving up to 100% accuracy using SVM. Importantly, specific wavenumbers showed statistically significant correlations with histological grade in both serum (1160 cm, p = 0.0114) and urine (1300 cm, p = 0.0375), indicating that the detected spectral features reflect tumor aggressiveness rather than merely cancer presence. The most influential variables were located in the amide II and urea-related region (1530-1545, 1695 cm) for urine, and in phosphate, phospholipid and lipid carbonyl regions (844-980, 1160-1164, 1700-1780, 2984-2992 cm) for serum, consistent with locally excreted protein and urea changes in urine and systemic lipid-metabolism alterations in serum. These findings demonstrate that FT-IR spectroscopy of both serum and urine enables identification of spectral biomarkers that correlate with clinically meaningful pathological parameters. The integration of spectroscopic data with medical characteristics strengthens biological interpretability and supports the potential of FT-IR as a minimally invasive tool for kidney cancer detection and stratification.
Europium(III)-functionalized covalent organic frameworks as fluorescent switches toward ultrasensitive detection of oxytetracycline.
Ren X, Zhang W, Wang Y … +3 more , Xu Y, Wang Y, Chen X
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42309028 · Publisher ↗
Tetracycline residues have raised widespread concern, among which oxytetracycline (OTC) has attracted particular attention because of its potential risks to human health. A sensitive analytical method for detecting tetra...
Tetracycline residues have raised widespread concern, among which oxytetracycline (OTC) has attracted particular attention because of its potential risks to human health. A sensitive analytical method for detecting tetracycline residues in complex samples is thus needed. Herein, a novel fluorescent sensing platform based on an europium(III) (Eu)-functionalized covalent organic frameworks (TpBy-COF) for the selective detection of OTC is developed. The fluorescence of TpBy-COF@Eu is hardly observed due to the non-radiative decay from coordinated water molecules. However, the fluorescence signals of TpBy-COF@Eu-based sensing platform is significantly enhanced with the introduction of OTC, attributed to the specific displacement of coordinated water molecules by OTC, which acts as an effective antenna ligand by transferring energy to the excited states of Eu,thereby sensitizing its characteristic red emission. Moreover, this TpBy-COF@Eu-based sensing platform exhibits the favorable sensitivity and selectivity for OTC monitoring with a low detection limit as low as 0.12 μmol/L. The TpBy-COF@Eu-based sensing platform is successfully validated in real samples, demonstrating the practical potential for OTC monitoring in complex matrices.
Mathematical and machine learning-assisted modelling of Raman spectroscopy for biomedical applications.
Servert Lerdo de Tejada J, Vališ J, Hrubčík L … +6 more , Janstová D, Tomeš J, Uhlíková T, Vazdar M, Mareš J, Matějka P
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42302682 · Publisher ↗
Over the past few decades, Raman spectroscopy has emerged as a powerful biomedical tool. Its non-destructive nature and sensitivity to subtle biochemical changes, particularly when combined with machine learning, have en...
Over the past few decades, Raman spectroscopy has emerged as a powerful biomedical tool. Its non-destructive nature and sensitivity to subtle biochemical changes, particularly when combined with machine learning, have enabled promising applications such as surgical assistance and cancer diagnosis. Nevertheless, there are still several challenges, including high data dimensionality, biological sample variability, and imbalanced datasets, which can limit its clinical potential. These challenges also complicate the design of reliable instrumentation and analytical software pipelines. In this critical review, we focus on mathematical and machine learning-assisted spectral generation methods that aim to enhance the applicability of Raman spectroscopy in biomedical research. We explore various spectral generation techniques, ranging from bottom-up approaches (like DFT and TD-DFT) that involve quantum mechanics simulations, to AI-assisted spectral generation techniques (such as GANs and Auto-encoders), while examining their advantages and limitations. Additionally, we discuss the challenges of transitioning Raman spectroscopy from controlled in vitro applications to comprehensive in vivo use. Instead of proposing new methodologies, we summarise and critically evaluate existing mathematical approaches that may assist with signal optimisation, safety analysis, and probe design. By making these methodologies more accessible, we outline open challenges and future directions to provide guidance with reduced costs, shorter development cycles, and improved safety profiles. Finally, we highlight open challenges and outline future research directions to inspire further progress in this field.
Raman spectroscopy coupled with PLS-CNN error-min fusion strategy for conformity discrimination and amino acid quantification in yeast extracts.
Zhao H, Li Z, Wu Y … +9 more , Zheng Z, Liu C, Huang X, Zhang Y, Lin D, Wang X, Wu Z, Chen M, Ruan Y
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42302681 · Publisher ↗
Yeast extract (YE) is a widely used bioproduct in the food and biofermentation industries, whose quality is determined by amino acid composition and conformity to industrial specifications. Conventional assessment relies...
Yeast extract (YE) is a widely used bioproduct in the food and biofermentation industries, whose quality is determined by amino acid composition and conformity to industrial specifications. Conventional assessment relies on amino acid analyzers and microbial growth assays, which are time-consuming and unsuitable for in situ monitoring. Raman spectroscopy offers a non-destructive alternative, but its application to complex biomolecular matrices such as YE is hindered by strong fluorescence backgrounds, spectral overlap, and heterogeneous linear/nonlinear relationships across multiple analytes. In this work, 1064 nm excitation was selected over 830 nm to suppress fluorescence interference and yield clearer spectral features. For conformity classification, a one-dimensional convolutional neural network (CNN) with channel attention achieved 92% accuracy, outperforming conventional classifiers. For amino acid quantification, a variable-wise PLS-CNN error-min fusion strategy was developed, in which the CNN contribution weight for each amino acid is independently optimized by minimizing validation error, enabling adaptive linear-nonlinear balancing across heterogeneous targets. The unified fusion model achieved coefficients of determination of 0.989 for hydrolyzed amino acids and 0.956 for free amino acids across mixed process types, outperforming standalone PLS, CNN, and other baselines. The framework was validated across standard, low-hydrolysis, high-hydrolysis, and high-nucleotide YE variants, demonstrating feasibility for rapid spectroscopic analysis of complex biomolecular matrices pending broader validation.
Research on concentration detection method for turbid solutions using multidimensional spectroscopy with a parabolic sample cell.
Zhang J, Zhang X, Ma Z
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42302680 · Publisher ↗
To address the difficulty of effectively utilizing scattering information in conventional optical methods for turbid solution concentration detection, this study presents a parabolic sample cell enabling rapid simultaneo...
To address the difficulty of effectively utilizing scattering information in conventional optical methods for turbid solution concentration detection, this study presents a parabolic sample cell enabling rapid simultaneous acquisition of multidimensional hyperspectral data. The parabolic incident surface produces non-cylindrically symmetric transmission spots, capturing richer spectral information while the variable curvature concentrates the spot and suppresses stray light. The structure also minimizes wall-reflection stray light from oblique incidence, ensuring high purity of the diffuse reflection signal. Monte Carlo simulations identified the parabolic cell with coefficient a = 0.04 as optimal. Partial least squares regression models established between intensity distribution data and the reduced scattering coefficient show that the parabolic cell achieves superior prediction accuracy over flat and hemispherical structures under both transmission and diffuse reflection conditions. Experimental validation using 60 Intralipid-20% samples demonstrates that the two-dimensional model based on the parabolic cell improves the test set coefficient of determination (Rₚ) by 1.11% over the hemispherical model, while the spatially resolved diffuse reflectance curve achieves a test set Rₚ of 0.9861. Thus, the proposed method significantly enhances detection accuracy, offering a promising approach for high-precision analysis of turbid solutions.
Detection and quantification of mold spores in wheat using hyperspectral imaging and data fusion techniques.
Wu W, Zhang Y, Wu Q … +2 more , Zhang D, Du G
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42302679 · Publisher ↗
Timely detection of mold severity is crucial for postharvest wheat quality and safety. This study developed a hyperspectral imaging (HSI) system integrated with chemometrics for the rapid, non-destructive quantification...
Timely detection of mold severity is crucial for postharvest wheat quality and safety. This study developed a hyperspectral imaging (HSI) system integrated with chemometrics for the rapid, non-destructive quantification of mold severity via spore count analysis. Spectral data were preprocessed, and key features were extracted using competitive adaptive reweighted sampling (CARS), successive projections algorithm (SPA), and uninformative variable elimination (UVE). These features were then fused with texture information derived from gray-level co-occurrence matrix (GLCM) analysis. Three predictive models were constructed and evaluated: least squares support vector machine (LSSVM), random forest (RF), and convolutional neural network (CNN). The 1ST-CARS-GLCM-CNN model, integrating fused spectral-textural features, delivered superior performance, achieving a test-set coefficient of determination (R) of 0.9904 and root mean square error (RMSE) of 0.1025, and enabled spatial distribution mapping for visual assessment. The HSI-chemometric approach effectively quantifies mold severity, providing a robust tool to enhance grain storage and food safety.
Enhanced and tunable white luminescence in NaGdGeO₄: Bi, Dy phosphors featuring anomalous thermal quenching.
Wang X, Jin T, Lu Z … +4 more , Zhou J, Tian W, Li J, Hu J
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42302678 · Publisher ↗
A novel series of NaGdGeO₄ phosphors co-doped with Bi and Dy ions were successfully synthesized via a conventional high-temperature solid-state reaction method. By systematically varying the Dy/Bi doping concentrations,...
A novel series of NaGdGeO₄ phosphors co-doped with Bi and Dy ions were successfully synthesized via a conventional high-temperature solid-state reaction method. By systematically varying the Dy/Bi 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: 0.01Bi, 0.05Dy 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 Bi to Dy 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 Bi (P → S) to Dy (F → H) and the direct excitation of Dy at 347 nm. This work highlights the significant potential of NaGdGeO₄: Bi, Dy phosphors for application in white light-emitting diodes, particularly where thermal management is critical.
Hydrolytic evolution of propyrisulfuron: wlectronic differentiation and spectroscopic fingerprints of transformation products.
Gong X, Xie Y, Deng X … +6 more , Sun Z, Fu S, Wang H, Hou Y, Dong Z, Zhou W
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42302677 · Publisher ↗
Propyrisulfuron (PRS), a sulfonylurea herbicide used in paddy systems, undergoes hydrolysis to form structurally distinct transformation products. This study combined DFT/TDDFT calculations with experimental UV-Vis, FTIR...
Propyrisulfuron (PRS), a sulfonylurea herbicide used in paddy systems, undergoes hydrolysis to form structurally distinct transformation products. This study combined DFT/TDDFT calculations with experimental UV-Vis, FTIR, and Raman spectroscopy to characterise PRS and six experimentally identified products (HP1-HP6). Relative electronic descriptors showed that cleavage of the sulfonylurea bridge increased the HOMO-LUMO gaps from 4.572 eV for PRS to 5.978 and 6.229 eV for HP1 and HP2, respectively, whereas HP3-HP5 retained moderate gaps of 4.846-4.923 eV. HP5 showed the most negative V (-71.524 kcal mol) and the largest dipole moment (16.67 D). Calculated and experimental spectra were consistent, with major UV-Vis peak deviations below 10 nm and characteristic FTIR and Raman deviations generally below 20 and 15 cm, respectively. A validated 1YBH-based docking workflow reproduced the co-crystallized CIE pose with an RMSD of 0.320 Å; within this internally standardized comparison, PRS, HP3, HP5, and HP4 gave scores of -8.480, -7.212, -7.076, and - 6.979 kcal mol, respectively. Docking results are interpreted as relative ALS/AHAS-recognition tendencies rather than direct evidence of toxicity or inhibitory potency. Overall, this work establishes a structure-spectrum framework for tracking PRS hydrolysis and differentiating its major products.
Linear and third-order non-linear spectroscopic investigations on novel dicyanodibenzodioxin dyes.
Jha VK, Patel SK, Banerjee S … +1 more , Iyer ESS
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42302676 · Publisher ↗
A comprehensive spectroscopic and computational investigation reveals how intramolecular charge-transfer (ICT) dynamics and two-photon absorption (2PA) properties can be systematically tuned in a series of dicyanodibenzo...
A comprehensive spectroscopic and computational investigation reveals how intramolecular charge-transfer (ICT) dynamics and two-photon absorption (2PA) properties can be systematically tuned in a series of dicyanodibenzodioxin (D(CBO)) derivatives. Steady-state absorption and fluorescence spectroscopy, femtosecond transient absorption (TA), quantum-chemical calculations, and open-aperture Z-scan measurements were combined to establish clear structure-property relationships governing their nonlinear optical response. The molecular design strategy incorporated controlled variation of the donor-acceptor strength through substitution with electron-withdrawing (Br, -CN, -NO₂) and electron-donating (piperazine, N, N-dimethylpiperazine, pyrazine) groups to modulate the extent of charge delocalisation and ICT character. Steady-state absorption spectra exhibited insubstantial solvatochromism, whereas fluorescence spectra showed pronounced red shift with increasing solvent polarity, confirming the formation of dipolar ICT states in selected derivatives. Lippert-Mataga analysis revealed that the change in dipole moment (Δμ) between the ground and excited states governs excited-state stabilisation and correlates with variations in fluorescence lifetimes. Transient absorption measurements demonstrated polarity-dependent relaxation pathways and multi-exponential decay kinetics associated with ICT state formation. Time-dependent density functional theory (TD-DFT) calculations support the experimental observations, demonstrating substituent-dependent modulation of frontier molecular orbital localisation and excited-state charge redistribution. Open-aperture Z-scan experiments further established that the 2PA coefficients scale with the degree of charge localisation, with the nitro-substituted derivative 3d exhibiting the fastest excited-state dynamics and the highest nonlinear two-photon absorption coefficient. The findings elucidate critical structure-property correlations that enable rational tuning of ICT and NLO behaviour in D(CBO)-based π-conjugated systems, offering design principles for high-performance molecules for applications like bio-imaging and optoelectronics.
Fluorescence detection strategy based on DNA tetrahedron and ATP-assisted signal amplification for intracellular hypochlorous acid imaging.
Chen Y, Zhou X, Chen F … +1 more , Ma C
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42296685 · Publisher ↗
Hypochlorous acid (HClO) serves as a vital reactive oxygen species within the immune system, facilitating defense against microbial invasion and maintaining immune homeostasis. However, excessive accumulation of HClO exe...
Hypochlorous acid (HClO) serves as a vital reactive oxygen species within the immune system, facilitating defense against microbial invasion and maintaining immune homeostasis. However, excessive accumulation of HClO exerts adverse effects on the body and acts as a critical driver of various neuroinflammatory and cardiovascular diseases. Herein, an detection strategy based on DNA tetrahedron nanostructure and ATP-assisted signal amplification was used for sensitive HClO analysis. The developed system exhibited a linear range of 0.01-3 μM, with a detection limit of 7.49 nM. The assay completed within 30 min, enabling efficient analysis of HClO. Finally, the proposed method was applied to fluorescence imaging of HClO in RAW 264.7 cells, showcasing its potential for intracellular analysis.
Efficient tuning and designing of donor-π-acceptor dyes for dye-sensitized solar cells and exploration of nonlinear optical property.
Kumar R, Singh P, Yadav V … +1 more , Singh A
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42296684 · Publisher ↗
The structural modification of boron dipyrromethene (BODIPY) organic dyes to improve their light-harvesting efficiency in dye-sensitized solar cells has been designed. Density functional theory (DFT) and time-dependent d...
The structural modification of boron dipyrromethene (BODIPY) organic dyes to improve their light-harvesting efficiency in dye-sensitized solar cells has been designed. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) based calculations were performed to investigate the structural, electronic and photovoltaic performance of designed dyes. To improve the dye performance, electron donating group tetra-methyl substituted julolidine group were introduced at terminal position of incorporated π-bridge. Computed results revealed that the introduction of electron donating group followed by π-bridge not only widens the absorption maxima while it narrows the band gap and also enhances the light harvesting efficiency and dipole moment. Further, we have examined the dye adsorption on surfaces of titanium dioxide (TiO) to assess the dye's performance.
Intelligent SERS sensing strategy based on Ag NP fractal networks and gradient kernel size CNN for high-precision sweat monitoring.
Li X, Yang X, Wang R … +6 more , Teng P, Gao S, Lu N, Li X, Jones A, Li K
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42296683 · Publisher ↗
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 intelligen...
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 to 10 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 R values of LA and Glu reached 0.99 and 0.98, respectively; for the joint dataset containing pure and mixed samples, the R 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.
Comparing post-acquisition methods for Raman-based mineral identification of particles in yellow earth pigments.
Johns MA, Handberg F, Groß H … +8 more , Boyadzhieva T, Laghrissi A, Zeeck T, Ayvaz S, Kunstmann-Olsen C, Rubahn HG, Kienle L, Fiutowski J
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42288097 · Publisher ↗
Natural yellow earth pigments are heterogeneous mineral assemblages dominated by iron (hydr)oxides and accompanied by variable accessory phases such as quartz, calcite, gypsum, and aluminosilicates. Although these access...
Natural yellow earth pigments are heterogeneous mineral assemblages dominated by iron (hydr)oxides and accompanied by variable accessory phases such as quartz, calcite, gypsum, and aluminosilicates. Although these accessory minerals may encode geological origin, their reliable identification from bulk Raman spectra is complicated by multiphase band overlap, fluorescence background, and particle-level heterogeneity. As a result, mineral discrimination from Raman data alone remains analytically demanding. Here, we examine whether systematic post-acquisition processing can enable robust mineral-based differentiation of closely related pigments using Raman spectroscopy alone. Five yellow earth pigments (three yellow ochres and two raw siennas) were analyzed using particle-resolved confocal Raman spectroscopy, generating statistically representative datasets (>200 spectra per sample). Mineral identification was performed using three strategies, visual interpretation, automated three-component spectral library fitting (3C model), and supervised machine learning classification (XGBoost), and assessed using a binary presence/absence scheme to support comparison across heterogeneous particle populations. Both the 3C and XGBoost approaches enabled statistical separation of all five pigments, whereas K-means cluster analysis of the visual interpretation did not distinguish between the two raw siennas. Together, these results support a reproducible Raman-only workflow for preliminary mineral assignment and pigment discrimination in provenance-oriented cultural heritage studies.
Spectroscopic investigation of near-infrared luminescence and energy band structure in Cr-doped BaGaO.
Zhang Y, Li K, Muji H … +6 more , Tian Q, Gao Y, Mai N, Gu X, Zhao F, Chao K
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42288096 · Publisher ↗
Cr activated broadband Near-Infrared (NIR) fluorescent phosphors with octahedral coordination preference and their potential applications in biomedicine, plant growth, etc. However, the development of Cr-doped broadband...
Cr activated broadband Near-Infrared (NIR) fluorescent phosphors with octahedral coordination preference and their potential applications in biomedicine, plant growth, etc. However, the development of Cr-doped broadband NIR fluorescent phosphors with tetrahedral coordination remains a challenge. This study, for the first time, employs first-principles calculations to investigate the doping sites of Cr in a tetrahedral coordination environment. It confirms the possibility of tetrahedral coordination for Cr and determines the doping sequence of Cr through the calculation of formation energies. The energy band structure of BaGaO:Cr has been calculated for the first time, and the orbital distribution of the Cr impurity energy level has been calculated by mBJ correction, which is in good agreement with the experimentally derived spectral leaps. The emission peak of BaGaO:Cr phosphor is located at 711 nm. XPS tests were conducted to determine the valence state of Cr ions in the lattice of BaGaO:Cr, confirming the presence of Cr ions responsible for NIR luminescence in BaGaO:Cr. Thermal stability tests were performed, showing that the thermal stability can reach 66.46% at 425 K under ambient conditions when single-doped with Cr, representing a significant improvement compared to other tetrahedrally coordinated Cr dopants. This provides possibilities for the application of Cr in tetrahedral coordination as near-infrared fluorescent phosphors for LEDs.
A multi-stimuli responsive Salicylaldehyde Hydrazone with high-contrast chromic behaviors, tetracycline sensing and multi-level anti-counterfeiting.
Li JL, Qian YX, Li Z … +7 more , Li X, Liu DY, Jia MR, Zheng HW, Jiao CQ, Zhu YY, Sun ZG
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42288095 · Publisher ↗
Stimuli-responsive materials have garnered significant attention due to their wide applications in sensors, information encryption, and intelligent optoelectronic devices. However, developing intelligent responsive mater...
Stimuli-responsive materials have garnered significant attention due to their wide applications in sensors, information encryption, and intelligent optoelectronic devices. However, developing intelligent responsive materials based on a single molecule that can achieve high contrast with diverse responses to multiple external stimuli remains a challenge. Herein, a salicylaldehyde hydrazone (HL), was synthesized via a solvothermal method. HL exhibited reversible multi-stimuli-responsive behaviors, including mechanochromism, photochromism, and acidochromism. Specifically, HL exhibits obvious responses in color and luminescence upon multi-stimuli. Mechanical grinding triggers distinct color changes from yellow to orange under ambient light, accompanied by a 40 nm bathochromic shift in fluorescence (from yellow-green to yellow), which can be restored via ethanol vapor fumigation. Upon ultraviolet irradiation, HL exhibits photochromism and photoswitchable luminescence, turning to orange under ambient light and its luminescence turning to beige in the solid state, with restoration achieved by heating or storage in the dark. Similar photo-responsive behavior is also observed in solution. HL also displays acid-responsive behavior, upon exposure to TFA vapor, the color and luminescence turn to brown and reddish-brown (from 500 nm to 675 nm, 175 nm bathochromic shift), respectively. It can also be restored under the TEA fumigation. Furthermore, HL showed "turn-off" fluorescent sensing of tetracycline (TC) with satisfactory sensitivity, selectivity, and low limits. Leveraging the multi-stimuli-responsive characteristics, HL and its PMMA-based flexible film were applied to multi-level dynamic information encryption and anti-counterfeiting. This work provides a robust strategy for the design of multi-stimuli-responsive materials.
Through-space charge transfer enables efficient carbonyl/amine multi-resonance emitters for organic light-emitting devices.
Li Y, Li XL, Kai CC … +5 more , Zhong LT, Wang RJ, Tan JH, Huo Y, Chen WC
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42288094 · Publisher ↗
Owing to their narrow-band emission and high color purity, multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters have emerged as promising contenders for ultra-high-definition organic light-emitt...
Owing to their narrow-band emission and high color purity, multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters have emerged as promising contenders for ultra-high-definition organic light-emitting diodes (OLEDs). However, carbonyl/amine MR-TADF systems are still plagued by sluggish reverse intersystem crossing (RISC) and severe aggregation-caused quenching (ACQ), limiting device efficiency and concentration tolerance. Herein, we propose a through-space charge-transfer (TSCT) strategy by integrating a spirolocked carbazole donor with a carbonyl/amine MR acceptor skeleton. The resulting emitter, tCON-SCFMe, exhibits controllable TSCT characteristics enabled by intramolecular π-stacking interactions, which effectively promote exciton upconversion while maintaining a small emission redshift and narrowband emission. Meanwhile, the sterically congested structure suppresses intermolecular quenching and enhances anti-aggregation capability. Consequently, the optimized OLED achieves greenish-blue emission at 488 nm with a maximum external quantum efficiency (EQE) of 20.2%. Notably, the OLED retains a high EQE of 14.6% at a doping concentration of 20 wt%, demonstrating excellent concentration tolerance. This study provides a robust molecular design for simultaneously regulating exciton dynamics and aggregation behavior in carbonyl/amine MR-TADF emitters for efficient narrowband OLEDs.
Quality control of traditional Chinese medicine solid preparation Zhizi Jinhua Pills via FT-IR, UV and THz fingerprints assisted with dissolution.
Wang X, Zou K, Li P … +5 more , Zhu W, Cui H, Xiao L, Lan L, Sun G
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42288093 · Publisher ↗
The chemical complexity and compositional diversity of traditional Chinese Medicine (TCM) and its proprietary preparations present substantial challenges to their quality control. Spectroscopic detection techniques repre...
The chemical complexity and compositional diversity of traditional Chinese Medicine (TCM) and its proprietary preparations present substantial challenges to their quality control. Spectroscopic detection techniques represent a powerful tool for TCM quality assessment owing to their rapidity, non-destructiveness, and environmental friendliness. Nevertheless, spectral information overlap has long impeded effective qualitative and quantitative analysis. In this study, Fourier transform infrared (FT-IR), ultraviolet (UV), and terahertz (THz) spectroscopic techniques were employed to establish multi-dimensional spectral fingerprints for Zhizi Jinhua Pills (ZZJHPs). Original spectra were processed using the quantum fingerprinting method, and qualitative similarity (S) and quantitative similarity (P) were further evaluated via the systematically quantified fingerprint method. Based on the integrated tri-spectral fingerprint analysis, 32 batches of ZZJHP samples were categorized into three distinct quality grades. In addition, the overall dissolution behavior of ZZJHPs was systematically investigated using a full ultraviolet fingerprint (FUV-FP) strategy. The established FUV-FP method enabled rapid and accurate characterization of in vitro dissolution profiles. Among all samples, two batches exhibited relatively slow dissolution rates, whereas four batches displayed faster release behavior, which was sensitively distinguished by the quantitative similarity parameter P. This work provides an effective strategy for resolving spectral information overlap in TCM spectroscopic analysis. It also promotes the application of UV fingerprinting for holistic dissolution evaluation, thereby offering a reliable and practical technical approach for the quality control of TCM solid preparations.
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