Spectrochimica Acta. Part A, Molecular And Biomolecular Spectroscopy[JOURNAL]
Sun
200 papers
Synergistic regulation of AIE property by J-/H-aggregates and TICT in a cationic iridium complex.
Yao W, Zhu Y, Jia X … +6 more , Liu C, Dong X, Hui Z, Li Z, Shui X, Song Z
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42242149 · Publisher ↗
The photophysical properties of phosphorescent iridium complexes are intricately governed by the interplay between intermolecular packing and intramolecular processes. In this work, we report a cationic iridium complex w...
The photophysical properties of phosphorescent iridium complexes are intricately governed by the interplay between intermolecular packing and intramolecular processes. In this work, we report a cationic iridium complex whose aggregation-induced emission (AIE) property is synergistically regulated by the formation of J- or H-aggregates and the twisted intramolecular charge transfer (TICT) effect inherent to its donor-acceptor ligand. The emission characteristics exhibit a pronounced dependence on the water fraction in THF/water mixtures. Through a combination of single-crystal analysis, AFM/HR-TEM, and TD-DFT calculations, we elucidate that specific non-covalent interactions dictate the molecular packing, while the TICT process, active in solution, is effectively suppressed upon aggregation. Additionally, solvation of the counter anion at elevated water fractions is identified as a critical factor contributing to emission quenching. This study provides deep insights into the cooperative roles of TICT and distinct aggregate types in manipulating the luminescence of iridium complexes, establishing a strategic guideline for the design of advanced AIE-active materials with highly promising practical applications in areas such as latent fingerprint identification and environmental stimuli-responsive smart sensors.
Structure-property relationships of pyrrolopyrrole Aza-BODIPYs: Substituent effects on NIR absorption and photosensitization.
Zhang E, Tian J, Liu Y … +4 more , Shen Y, Zeng S, Wang Y, Zheng F
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42242148 · Publisher ↗
Unraveling the structure-photophysics relationship is crucial for the rational design of organic near-infrared (NIR) photosensitizers. Herein, we report the synthesis and systematic spectroscopic characterization of a se...
Unraveling the structure-photophysics relationship is crucial for the rational design of organic near-infrared (NIR) photosensitizers. Herein, we report the synthesis and systematic spectroscopic characterization of a series of pyrrolopyrrole aza-BODIPY (PPAB) derivatives functionalized with eight distinct peripheral substituents. Through a combination of photophysical measurements and time-dependent density functional theory (TD-DFT) calculations, we explored the substituent effects on their optical properties and singlet oxygen (O) generation capacities. While substituent modulation exerted minimal perturbation on the highly localized electronic core (maintaining stable NIR absorption near 670 nm), it profoundly dictated the photosensitization efficiency, with O quantum yields varying dramatically from 4.34% to 41.65%. Spectroscopic analysis reveals that rigid peripheral substituents effectively restrict non-radiative decay pathways, whereas flexible or rotatable moieties (e.g., biphenyl, tetraphenylethylene) dissipate excited-state energy via intense intramolecular motions, significantly outcompeting the intersystem crossing (ISC) process. Furthermore, the biological applicability of these PPAB derivatives was validated. In vitro cellular studies demonstrated that they can rapidly localize in lysosomes and effectively produce singlet oxygen (O) in HeLa cells. This work provides deep photophysical insights into the molecular engineering of PPAB-based NIR chromophores, highlighting the critical role of restricting intramolecular motions for optimizing photosensitization.
Ellagitannins as Al(III) chelators: Determined binding sites with a predictive model.
Frešer F, Tähtinen P, Tošović J … +2 more , Bren U, Hostnik G
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42242147 · Publisher ↗
Plant-toxic Al(III) ions released in acidic soils pose a global problem, affecting a substantial portion of agricultural land. One plant defense mechanism against Al(III) ions, which is poorly understood, is the release...
Plant-toxic Al(III) ions released in acidic soils pose a global problem, affecting a substantial portion of agricultural land. One plant defense mechanism against Al(III) ions, which is poorly understood, is the release of organic acids or polyphenols with chelating properties. These compounds include ellagitannins (vescalin, castalin, vescalagin, castalagin, roburin A, and roburin D), whose chelating ability against Al(III) ions was investigated in this study. The formation of coordination compounds was monitored by Job's method at pH 3.5-5.5. NMR and CD spectroscopy, combined with DFT calculations, were used to determine the binding positions of Al(III) ions on these high-molecular-weight polyphenols. Using information about binding sites and the microscopic protolytic equilibrium of ellagitannins, a model was developed to describe and predict the chelating ability of Al(III) ions by the nonahydroxytriphenoyl and hexahydroxydiphenoyl groups of ellagitannins. This model was then fitted to the experimental Job plots. The obtained stoichiometries and apparent formation constants can be used to predict the Al(III) chelating ability of other ellagitannins with identical structural elements. The developed model can therefore serve as a predictive tool for the removal of Al(III) ions by ellagitannins at various pH values.
Enhanced synergistic tumor phototherapy based on engineered MXene/AgInS₂ quantum dot heterostructures.
Jia J, Zhao X, Feng S
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42242146 · Publisher ↗
The development of nanomaterial-based synergistic phototherapeutic platforms represents a promising strategy for efficient cancer treatment. Herein, we report the rational design and fabrication of a novel heterostructur...
The development of nanomaterial-based synergistic phototherapeutic platforms represents a promising strategy for efficient cancer treatment. Herein, we report the rational design and fabrication of a novel heterostructure by integrating AgInS₂ quantum dots (AIS QDs) with monolayer Ti₃C₂Tₓ MXene nanosheets (denoted as AIS + MX) via a facile thiol-metal coordination strategy. This composite nanomaterial synergistically combines the exceptional fluorescence properties and reactive oxygen species (ROS) generation capability of AIS QDs with the outstanding photothermal conversion efficiency and large specific surface area of MXene. Comprehensive characterization, including electron microscopy, spectroscopic analysis, and zeta potential measurements, confirmed the successful formation of the heterostructure. The AIS + MX composite demonstrated a remarkable photothermal conversion efficiency under 808 nm laser irradiation (0.6 W/cm for 10 min), with a temperature increase capable of reaching 56 °C at a concentration of 100 μg/mL. Furthermore, it exhibited significantly enhanced singlet oxygen (O₂) generation compared to its individual components, as verified by SOSG assays. In vitro studies revealed excellent biocompatibility of AIS + MX in the dark. Upon near-infrared (NIR) light irradiation, it achieved a superior synergistic photothermal/photodynamic effect, resulting in over 95% ablation of HeLa cells. This work highlights the great potential of MXene-based heterostructures as a powerful and versatile platform for synergistic cancer phototherapy.
A novel carbazole-type ratiometric fluorescent probe from natural nopinone for ultrasensitive and visual detection of BPO and its application in food and cosmetic samples.
Zhang S, Meng Z, Ye Q … +6 more , Yang Y, Li J, Li L, Wang Z, Yang J, Wang S
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42242145 · Publisher ↗
Benzoyl peroxide (BPO) is a common flour whitening agent and cosmetic additive. However, BPO may decompose into toxic and harmful substances such as biphenyl and benzyl benzoate, which will enter the human body through f...
Benzoyl peroxide (BPO) is a common flour whitening agent and cosmetic additive. However, BPO may decompose into toxic and harmful substances such as biphenyl and benzyl benzoate, which will enter the human body through foods or the skin, and affect human health. In this study, A novel carbazole-type ratiometric fluorescent probe BTHC-PC-BB with a large Stokes shift (230 nm) was synthesized from natural nopinone, and was used for the detection of BPO in foods and cosmetics samples. Furthermore, a gel beads sensor for detecting BPO was designed and fabricated based on the specific reaction between BTHC-PC-BB and BPO, which exhibited significant color change in the presence of BPO with different concentrations, and provided a new method for the visual detection of BPO.
Label-free imaging and machine learning reveal cyclin-dependent kinase 6 (CDK6)-regulated metabolic phenotypes and beige potential in single preadipocytes.
Zhou Y, Xu Y, Cheng S … +5 more , Ni X, Zhang L, Zhang X, Hou X, Xia D
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42242144 · Publisher ↗
Cyclin-dependent kinase 6 (CDK6) regulates adipogenesis and beige fat formation, but its role in preadipocyte metabolism is unclear. The mouse embryonic fibroblast cell line 3 T3-L1 is a well-established preadipocyte mod...
Cyclin-dependent kinase 6 (CDK6) regulates adipogenesis and beige fat formation, but its role in preadipocyte metabolism is unclear. The mouse embryonic fibroblast cell line 3 T3-L1 is a well-established preadipocyte model with high adipogenic potential under adipogenic stimulation. Here, we employed label-free, non-invasive Raman imaging to investigate the metabolic profile of 3 T3-L1 cells following CDK6 knockout (KO) at the single-cell level. To improve the specificity of spectral interpretation, isolated cellular mitochondria and mouse skin tissue were used as reference standards for mitochondrial and collagen Raman fingerprints, respectively. True component analysis (TCA) was applied to Raman hyperspectral datasets to decompose complex spectral signals into distinct biochemical components with corresponding spatial distributions. Compared to wild-type (WT) cells, CDK6 ablation increased mitochondrial content and the unsaturated-to-saturated fatty acid ratio, but reduced collagen and overall lipid content. These shifts suggest that CDK6 deletion promotes mitochondrial metabolism and suppresses extracellular matrix synthesis, thereby conferring beneficial metabolic changes that support differentiation potential toward beige adipocytes. Four Raman spectral biomarkers (I, I, I, I) enabled effective cell-type discrimination. For hyperspectral data processing, we employed a machine learning-based pipeline comprising preprocessing (baseline correction and normalization), dimensionality reduction via principal component analysis (PCA), and classification using multiple algorithms. Among these, the linear discriminant analysis (LDA) model achieved the highest classification accuracy of 98.3% in discriminating WT and KO cells. This study demonstrates that Raman spectroscopy not only enables label-free analysis of subtle metabolic phenotypes at the single-cell level but also provides a novel platform for predicting adipocyte differentiation fate.
A novel non-destructive approach for cashmere authenticity: Combining spectroscopic techniques and machine learning algorithms.
Wan C, Li R, Xie J … +3 more , Chen F, Yu W, Liu Y
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42242143 · Publisher ↗
Cashmere is a high-value animal fiber often adulterated with cheaper sheep-down due to their visual similarity and significant cost difference. Traditional identification methods are subjective and limited, while more ac...
Cashmere is a high-value animal fiber often adulterated with cheaper sheep-down due to their visual similarity and significant cost difference. Traditional identification methods are subjective and limited, while more accurate biological techniques are costly and time-consuming. Spectroscopy offers a promising alternative, though efficient and reliable discrimination remains challenging. This study aims to develop an accurate and efficient method for distinguishing pure cashmere from sheep-down and their blends using near-infrared (NIR) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy combined with machine learning algorithms. A total of 200 cashmere and 200 sheep-down fiber samples were analyzed using NIR and ATR-FTIR spectroscopy. Spectral data were processed using principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), data-driven soft independent modeling of class analogy (DD-SIMCA), and convolutional neural networks (CNN). Blended samples (10-50% sheep-down) were simulated via a linear mixing model. PLS-DA and DD-SIMCA models showed limited accuracy (41-73%), with ATR-IR-based models generally outperforming NIR. The CNN model, particularly using ATR-IR data, achieved perfect classification (100% sensitivity, specificity, and accuracy) for both pure and blended samples, significantly surpassing traditional chemometric methods. The ATR-IR-CNN approach provides a rapid, non-destructive, and highly accurate method for cashmere authentication, offering a robust solution to combat adulteration, protect consumers, and enhance quality control in the textile industry.
Lysosome-targeted near-infrared fluorescent probes for monitoring aβ plaques in vivo and aβ monomers dynamic degradation in vitro.
Gong H, Li Z, Zhao Y … +2 more , Wang Z, Luo W
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42242142 · Publisher ↗
The aggregation of β-amyloid (Aβ) is a central pathological feature of Alzheimer's disease (AD), with its dynamic changes closely linked to disease progression. Lysosomes play a critical role in the clearance and degrada...
The aggregation of β-amyloid (Aβ) is a central pathological feature of Alzheimer's disease (AD), with its dynamic changes closely linked to disease progression. Lysosomes play a critical role in the clearance and degradation of Aβ, making them an important focus in AD research. In this study, a series of multifunctional lysosome-targeting near-infrared fluorescent probes based on a dicyanoisophorone scaffold were developed to enable simultaneous targeting of lysosomes and monitoring of Aβ aggregates. All probes effectively localized within cellular lysosomes, with NCM-4 demonstrating the most efficient lysosomal targeting, along with high selectivity, specificity, and strong binding affinity toward Aβ aggregates. Both in vivo imaging and ex vivo brain slice staining confirmed that the probe efficiently crossed the blood-brain barrier and selectively accumulated in the brains of APP/PS1 transgenic mice, allowing clear visualization of Aβ plaques. Furthermore, due to its lysosomal localization, NCM-4 enabled real-time tracking of the internalization of FITC-labeled Aβ monomers (Aβ) from the extracellular environment into lysosomes. This capability also allowed monitoring of how autophagy modulation, via chloroquine and rapamycin, influences Aβ clearance within lysosomes. Overall, these probes, particularly NCM-4, provide a valuable platform for AD diagnosis and offer powerful tools for studying lysosome-mediated Aβ clearance mechanisms and therapeutic interventions.
Non-invasive urinary FTIR spectroscopy for early diagnosis and monitoring of diabetic nephropathy.
Ding J, Fang Z, Feng L … +5 more , Li X, Shi J, Zhou X, Huang P, Lin H
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42242141 · Publisher ↗
Diabetic nephropathy (DN) is a progressive and life-threatening complication of diabetes mellitus (DM). However, developing sensitive and specific non-invasive diagnostic approaches remains a critical clinical challenge....
Diabetic nephropathy (DN) is a progressive and life-threatening complication of diabetes mellitus (DM). However, developing sensitive and specific non-invasive diagnostic approaches remains a critical clinical challenge. In this study, we characterized the biochemical and metabolic alterations in the kidney and urine using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy in a type 2 diabetic db/db mouse model at 7, 12, and 21 weeks. Spectral analysis revealed distinct, time-dependent disruptions in the vibrational bands associated with protein, lipid, and carbohydrate components in both kidney and urine samples. Principal component analysis (PCA) effectively distinguished diabetic mice from controls, capturing spectral alterations associated with the progression of DN. Based on these discriminative features, we established two independent machine learning frameworks for kidney and urine data to classify temporal groups and to evaluate whether urinary spectral profiles could non-invasively reflect renal pathology. Among all evaluated classifiers, Partial Least Squares Discriminant Analysis (PLS-DA) exhibited the highest classification accuracy across time points, achieving 97.50% for renal spectra and 92.50% for urinary spectra. To quantitatively assess renal injury, we developed a partial least squares regression (PLSR) model using renal spectra to predict hematoxylin and eosin (H&E)-derived scores. Furthermore, urinary FTIR spectra were used to predict renal H&E scores, and a strong linear correlation was observed between predicted and reference values. This analysis revealed a strong association between urinary FTIR spectra and histologically derived renal injury scores (R = 0.846), indicating that urinary spectral signatures are significantly associated with renal pathological changes in this model. Collectively, these findings support urinary FTIR profiling as a rapid, cost-effective, and non-invasive complementary approach to traditional tissue-based assessments of DN, enabling early detection and longitudinal monitoring of the disease. Future studies should evaluate the clinical validity and translational applicability of this technique in independent cohorts.
Evaluation of porcine ear skin as a model for human skin: influence on the diffusion of different photosensitizers.
Braga TL, de Castro-Hoshino LV, Dos Santos JJ … +4 more , Pozza PC, de Freitas CF, Baesso ML, Caetano W
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42242140 · Publisher ↗
Porcine ear skin is widely employed as an ex vivo biological interface for investigating molecular interactions between bioactive compounds and skin tissue due to its structural and compositional similarity to human skin...
Porcine ear skin is widely employed as an ex vivo biological interface for investigating molecular interactions between bioactive compounds and skin tissue due to its structural and compositional similarity to human skin. In this study, we analyze how structural maturation of the cutaneous biointerface as a function of age influences the interaction and diffusion behavior of three bioactive photosensitizers, curcumin, erythrosine B, and methylene blue, within porcine ear skin. Skin samples were obtained from animals aged 40, 75, 115, and 150 days, corresponding approximately to body masses of 10, 40, 70, and 100 kg, in order to evaluate progressive tissue maturation effects. Photoacoustic spectroscopy (PAS) was employed as an optical and thermal technique sensitive to biointerface properties to probe molecular absorption profiles within superficial regions of the epidermis and dermis. Complementary characterization was performed using attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) combined with principal component analysis (PCA) to identify age-related molecular and compositional changes in skin tissue. The spectroscopic analyses revealed that structural modifications associated with collagen reorganization are more pronounced in the dermis, whereas the epidermis remains comparatively less affected as tissue maturation progresses. Following topical application of the photosensitizers (PSs), PAS measurements demonstrated that molecular interaction and diffusion behavior within the dermal region depend on both the physicochemical properties of the compounds and the structural state of the tissue. Among the investigated photosensitizers, methylene blue exhibited the highest sensitivity to biointerface maturation, whereas curcumin and erythrosine B showed comparatively limited variation. These findings highlight the role of age-dependent structural features of the cutaneous biointerface in modulating molecular interactions within skin tissue. By integrating PAS and FTIR-ATR, this work provides insight into how biological interface maturation influences the optical and molecular response of skin to bioactive compounds, contributing to the broader understanding of biointerface science.
Regulatory mechanism of nitrile substitution position on the excited-state intramolecular proton transfer kinetics and fluorescent properties of 2-(2'-hydroxyphenyl)benzoxazole derivatives.
Li C, Li J, Hu B … +1 more , Cao Y
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42242139 · Publisher ↗
Excited-state intramolecular proton transfer (ESIPT) is a key photophysical process of fluorescent molecules, whose dynamic properties are highly dependent on molecular structure modification. In this study, the ESIPT be...
Excited-state intramolecular proton transfer (ESIPT) is a key photophysical process of fluorescent molecules, whose dynamic properties are highly dependent on molecular structure modification. In this study, the ESIPT behaviors of eight 2-(2'-hydroxyphenyl)benzoxazole (HBO) derivatives with -CN substituents at different positions were systematically investigated. Through configuration optimization, potential energy curve scanning, electron density topological analysis, and spectral calculations, the structural and performance differences between representative derivatives 4-CN-HBO and 7-CN-HBO were focused on and compared. The results show that the position of the -CN substituent significantly regulates the intramolecular hydrogen bond strength, orbital energy levels, charge distribution, and ESIPT energy barrier. Introducing a -CN group onto the benzoxazole moiety can enhances the hydrogen bond interaction (21.21 kcal/mol), reduces the ESIPT energy barrier (0.53 kcal/mol), and accelerates ESIPT (22 fs); in contrast, substitution on the phenol moiety produces the opposite effect, the ESIPT energy barrier of 7-CN-HBO is as high as 3.55 kcal/mol, and the ESIPT time is prolonged to 61 fs. The electron-withdrawing CN group reconstructs the charge distribution. Substitution on the benzoxazole moiety promotes electron transfer from the phenol moiety to the benzoxazole moiety, increasing the basicity of the proton acceptor and facilitating ESIPT; substitution on the phenol moiety reverses the direction of charge transfer and inhibits the ESIPT. In addition, the keto fluorescence peak of 4-CN-HBO is red-shifted by 110.6 nm compared with that of HBO, while the spectral characteristics of 7-CN-HBO are close to those of HBO. This study reveals the regulatory law of substituent position on ESIPT dynamics and provides a crucial theoretical guidance for design of ESIPT-based fluorescent materials.
Archaeometric study of the Herculaneum soldier's weapon set and the impact of past conservation treatments.
Huidobro J, Costantini I, Veneranda M … +12 more , Etxebarria I, Vázquez de la Fuente I, Puente-Muñoz S, Prieto-Taboada N, Di Girolami G, Caso M, Canna E, Camardo D, Laino N, Castro K, Madariaga JM, Arana G
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42242138 · Publisher ↗
This research presents the first comprehensive archaeometric study of metallic artifacts recovered from the Herculaneum Archaeological Park, with a focus on the prestigious Herculaneum soldier's weapon set, discovered in...
This research presents the first comprehensive archaeometric study of metallic artifacts recovered from the Herculaneum Archaeological Park, with a focus on the prestigious Herculaneum soldier's weapon set, discovered in the 1980s during the excavations along the ancient shoreline. The primary objective of this study was to characterize the original composition of the soldier's equipment and identify the corrosion products present in the set. Furthermore, in-situ non-destructive measurements and laboratory-based analyses were conducted to evaluate the conservation status of the set. Analytical results revealed extensive silver halidization on the decorative belt and sword, with chlorargyrite identified as the predominant corrosion product, alongside bromide-related phases indirectly inferred from elemental data. The iron components of the belt and the dagger exhibited iron corrosion, primarily consisting of magnetite and goethite. Notably, the investigation also identified a suite of sulfur-rich compounds within the dagger's wooden scabbard, including pyrite, ammoniojarosite, boussingaultite and mirabilite. These mineral phases are attributed to a common, now-obsolete, early 20th century conservation treatment based on the impregnation of submerged wooden artifacts with alum solutions which subsequently interacted with the corroding metallic core. The subsequent recrystallization of these salts results in severe structural decay of the wooden components, highlighting the urgent need for conservation treatments to stabilize the wooden part of the dagger and prevent further damage.
Anthocyanin-based colorimetric sensor for aflatoxin B1 (AFB1) detection in wheat: Performance optimization via near-infrared (NIR) spectral characterization and structurally improved recurrent neural network (RNN).
Mei C, Hou Y, Zhou X … +2 more , Zhu J, Jiang H
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42242137 · Publisher ↗
The highly toxic aflatoxin B1 (AFB1) in wheat poses a severe threat to food security and public health. In this study, a rapid and eco-friendly detection method for AFB1 residues in wheat was developed by integrating a n...
The highly toxic aflatoxin B1 (AFB1) in wheat poses a severe threat to food security and public health. In this study, a rapid and eco-friendly detection method for AFB1 residues in wheat was developed by integrating a natural anthocyanin-based colorimetric sensor array (CSA) with near-infrared spectroscopy (NIRS). A Deep-RNN regression model was specifically constructed for the high-dimensional spectral sequence features of the natural anthocyanin-based CSA-NIRS coupled system, to achieve precise extraction of the core response characteristics correlated with AFB1. The results demonstrated that NIRS effectively expanded the feature dimension of CSA; models built on NIR spectral features achieved significantly higher recognition accuracy than traditional RGB-based models, and the optimized Deep-RNN model reached a quantitative prediction accuracy of over 0.90 for AFB1. This coupled system breaks through the limitations of conventional detection technologies, and provides a novel and reliable solution for on-site rapid screening of mycotoxins in cereal grains.
High-sensitive detection of Heritage Lakes via TLC-SERS Optochemical coupling.
Zhang B, Sun X, Mao H … +8 more , Campanella B, Legnaioli S, You R, Wu Z, Jia H, Chen Z, Yang H, Qiu J
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42235453 · Publisher ↗
The analysis of organic dyes in historical artifacts is crucial for understanding ancient artistic techniques and conservation practices. However, the accurate identification of these dyes remains challenging because dye...
The analysis of organic dyes in historical artifacts is crucial for understanding ancient artistic techniques and conservation practices. However, the accurate identification of these dyes remains challenging because dye components in artworks are often highly complex and under certain spectroscopic analytical techniques, in particular of conventional Raman spectroscopy, their chromophoric molecules frequently generate strong fluorescence backgrounds that obscure the desired Raman signals. To overcome this limitation, thin-layer chromatography (TLC) was photochemically coupled with surface-enhanced Raman scattering (SERS) to establish an integrated separation and identification approach for the analysis of complex organic dyes. This strategy was applied to the investigation of anthraquinone-based red lakes extracted from ancient tapestries. The chromatographic separation step effectively reduced spectral interference arising from the coexistence of multiple components in the samples, thereby enabling the spatial separation of structurally similar dye species. Subsequently, silver nanoparticles were introduced to enhance the local electromagnetic field surrounding the chromophores. The Raman signals were amplified by several orders of magnitude, allowing the acquisition of clear and reliably assignable vibrational fingerprints. Experimental results demonstrate that the TLC-SERS approach enables the reliable identification of anthraquinone dyes in real historical textile samples, providing an effective experimental strategy for identification of related dyes in the field of cultural heritage conservation and restoration.
Prediction of nutritional quality characteristics of faba bean based on deep learning method.
Dang B, Jin X, Zhang J … +3 more , Wu H, Wang M, Han L
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42235452 · Publisher ↗
This study established an integrated analytical method based on near-infrared spectroscopy (NIRS) for the rapid, non-destructive, and quantitative detection of four major nutritional components in faba beans: starch, pro...
This study established an integrated analytical method based on near-infrared spectroscopy (NIRS) for the rapid, non-destructive, and quantitative detection of four major nutritional components in faba beans: starch, protein, moisture, and dietary fiber. By systematically comparing individual and combined spectral preprocessing strategies, optimal preprocessing combinations for each component were identified. Seven feature wavelength selection algorithms, including Competitive Adaptive Reweighted Sampling (CARS), were employed to extract key spectral variables. Predictive models were subsequently developed using four modeling approaches: Partial Least Squares (PLS), Random Forest (RF), Support Vector Machine (SVM), and Multilayer Perceptron (MLP). The results demonstrated that combined preprocessing methods significantly outperformed single techniques. The CARS algorithm exhibited the most robust performance in feature extraction, and the MLP model consistently surpassed traditional machine learning methods in predicting all components. The optimal modeling pipelines for each component were ultimately determined as follows: starch (MLP + CARS + MSC + SG + MSS, R = 0.92), protein (MLP + CARS + SD + SNV + MSC + MSS, R = 0.94), moisture (MLP + SPA + SG + SNV, R = 0.9973), and dietary fiber (MLP + PCA + FD + SNV, R = 0.9999). This study verifies the effectiveness of combining NIRS with deep learning for the simultaneous detection of multiple components in faba beans and provides a reliable methodological framework for the non-destructive quality assessment of agricultural products.
Comparative study of interactions in highly concentrated sodium triflate and sodium bis(trifluoromethanesulfonyl)imide solutions in N,N-dimethylformamide-water mixture.
Tao Y, Li Z, Long L … +1 more , Jia X
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42235451 · Publisher ↗
Ion solvation and association critically influence electrolyte performance, yet how these interactions are modulated in mixed solvents remains unclear. Herein, we investigate highly concentrated NaOTf and NaTFSI solution...
Ion solvation and association critically influence electrolyte performance, yet how these interactions are modulated in mixed solvents remains unclear. Herein, we investigate highly concentrated NaOTf and NaTFSI solutions in DMF-water (1:1) using FT-IR, Raman spectroscopy, and DFT calculations. NaTFSI induces more pronounced spectral changes than NaOTf, including crystalline hydrate features in the OH stretching region and larger downshifts of the CO stretching band. Quantitative analysis shows Na preferentially coordinates with DMF regardless of the anion. At high concentrations, stronger ion association in OTf solutions decreases Na availability for DMF coordination, while weaker association and higher Na availability are observed for TFSI. DFT confirms that DMF substitution for water is thermodynamically favorable. These findings provide molecular-level insights for designing advanced sodium battery electrolytes.
Mechanofluorochromic properties of fluorenone-based triphenylamine- functionalized chalcone derivatives and their applications in information encryption.
Liu B, Liu H, Su Y … +3 more , Bai J, Zhang H, Jia J
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42235450 · Publisher ↗
In this study, three new aggregation-induced emission (AIE)-active chalcone derivatives based on triphenylamine and fluorenone, namely (E)-2-(4-(3-(4-(diphenylamino)phenyl)acryloyl)phenyl)-9H-fluoren-9-one (DPAPF), (E)-2...
In this study, three new aggregation-induced emission (AIE)-active chalcone derivatives based on triphenylamine and fluorenone, namely (E)-2-(4-(3-(4-(diphenylamino)phenyl)acryloyl)phenyl)-9H-fluoren-9-one (DPAPF), (E)-2-(4-(3-(4-(bis(4-bromophenyl)amino)phenyl)acryloyl)phenyl)-9H-fluoren-9-one(BAPAPF), and (E)-2-(4-(3-(4-(bis(4-bromophenyl)amino)phenyl)acryloyl)phenyl)-9H-fluoren-9-one (DTPAPF), have been designed, synthesized and fully characterized. Photophysical investigations and theoretical calculations revealed that these donor-acceptor (D-A) molecules adopt highly distorted non-planar conformations and exhibit distinct intramolecular charge transfer (ICT) characteristics. All three compounds display remarkable AIE properties in DMF/H₂O binary solvent mixtures. Moreover, DPAPF, BAPAPF and DTPAPF exhibit obvious mechanofluorochromic (MFC) behavior, upon grinding, their emission maxima show significant bathochromic shifts of 48 nm, 24 nm, and 62 nm, respectively. Powder X-ray diffraction (PXRD) and field-emission scanning electron microscopy (FESEM) analyses confirm that the reversible MFC response originates from crystal-to-amorphous phase transitions in the solid state. Single-crystal structural analysis further reveals that weak intermolecular interactions can be readily disrupted by external mechanical force, which favors the MFC effect. The planarization of molecular conformations and the subsequent planar intramolecular charge transfer (PICT) process are proposed to be responsible for the bathochromic shift upon grinding. Benefiting from their reversible high-contrast mechanofluorochromism, these luminogens demonstrate excellent application potential in anti-counterfeiting and multi-level information encryption.
From hydrogen-bond networks to multilevel encryption: Full-color fluorescence and controllable RTP activation of arylboronic acids via solvent-mediated cocrystal engineering.
Di L, Yang C, Cao Q … +8 more , Zhao M, Zhang Y, Wang H, Wang L, Xing Y, Yao J, Zhang T, Yang Z
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42235449 · Publisher ↗
Arylboronic acid derivatives have attracted much attention due to their inherent room-temperature phosphorescence (RTP). However, clarifying the structural basis of photoluminescence (PL) and guiding applications poses c...
Arylboronic acid derivatives have attracted much attention due to their inherent room-temperature phosphorescence (RTP). However, clarifying the structural basis of photoluminescence (PL) and guiding applications poses challenges. Using 4-bromophenylboronic acid (BrBA) as a model, the decisive regulation mechanism of hydrogen-bond networks on PL is first elucidated via cocrystal engineering. Specifically, the cross-shaped assemblies in BrBA cocrystals feature two distinct types of hydrogen-bond channels: the α-channel governs fluorescence (FL), whereas the β-channel specifically controls phosphorescence. The co-crystalline solvents, n-hexane and methanol, mediate the construction and dissociation of these hydrogen-bonding networks by modulating molecular packing, thereby precisely regulating PL behavior. Based on this solvent-mediated strategy, FL color regulation of BrBA and phenylboronic acid (BA) over nearly the entire visible spectrum (covering blue, green, yellow, orange), and controllable RTP activation are achieved without chemical modification. Furthermore, multilevel information encryption, including graphical, computational, and textual encryption is successfully demonstrated using the multicolor BrBA fluorescent powders. This study establishes a novel paradigm for the rational design and controllable preparation of pure organic RTP materials.
In vivo resonance micro-Raman spectroscopy study of Artemia salina (Linnaeus, 1758) carotenoids profile as proxy for variability in hypersaline lakes environmental conditions.
Maškarić K, Nesterovschi I, Molnár CM … +2 more , Nekvapil F, Pînzaru SC
Spectrochim Acta A Mol Biomol Spectrosc · 2026 Jun · PMID 42235448 · Publisher ↗
The brine shrimp Artemia salina (Linnaeus, 1758) has been used for ecotoxicity testing, both in field and laboratory settings. Carotenoid composition of A. salina plays a role in mitigation of physiological stress and ma...
The brine shrimp Artemia salina (Linnaeus, 1758) has been used for ecotoxicity testing, both in field and laboratory settings. Carotenoid composition of A. salina plays a role in mitigation of physiological stress and maintaining homeostasis. We exploited the fact that carotenoids are easily detectable under resonance Raman (RR) conditions by conducting in-vivo Raman measurements on A. salina. Here we report for the first time the in vivo characterization of A. salina pigments using RR spectroscopy and, based on these results we further explored the carotenoid profile of this crustacean as a proxy to readout the environmental parameters variability of hypersaline lakes from a balneary resort during cold and warm season. The in vivo carotenoids characterization is feasible using RR spectroscopy, Lorentz deconvolution of the main carotenoid ν(C=C) band revealed up to five peaks; implying spatio-temporal variations in carotenoid species content. Spectral features of peak positions and area of these deconvoluted bands revealed variations between cold and warm season. Contribution of specific carotenoid species can be connected to parameters such as salinity and nutritional resource availability which affect conversion of carotenoids by A. salina. These findings demonstrate in-vivo Raman measurements of A. salina could provide relevant and valuable informations for ecological, ecotoxicological, and biological studies of A.salina.
Substituent-triggered cross-phase inversion of excimer formation.
Zhao H, Xu J, Chen W … +4 more , Zhao Y, Yuan Y, Luo C, Xia G
Spectrochim Acta A Mol Biomol Spectrosc · 2026 May · PMID 42235447 · Publisher ↗
Excimer formation is governed by distinct dynamic and static mechanisms in solution and crystalline states, yet their intrinsic correlation remains poorly understood. Here we report a striking substituent-triggered cross...
Excimer formation is governed by distinct dynamic and static mechanisms in solution and crystalline states, yet their intrinsic correlation remains poorly understood. Here we report a striking substituent-triggered cross-phase inversion of excimer formation in a series of acridine derivatives. In solution, unsubstituted acridine (AD-H) and 9-phenylacridine (AD-Ph) readily form dynamic excimers at elevated concentrations, whereas the 2-methoxy-substituted analogue (AD-Ph-OMe) exhibits exclusively monomeric emission due to steric hindrance and enhanced hydrogen-bonded solvation. In the crystalline state, this trend is fully reversed: AD-Ph-OMe self-assembles into discrete slipped face-to-face dimers (d = 3.481 Å and S = 90.2%), preorganized by directional Ar-H···O interactions, giving rise to intense excimer emission at ∼494 nm with a high photoluminescence quantum yield of 64.8%, while AD-Ph shows only partial excimer contribution and AD-H exhibits none. This study highlights how subtle substituent modulation can invert excimer propensity across phases, providing molecular-level insight into aggregation-controlled photophysics and the design of discrete excimer emitters.
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