Lin K, Yao B, Wang Z
… +1 more, Zehnacker-Rentien A
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42335703
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Weak molecular interactions and subtle conformational variations can directly modulate CH bond strength, yet their spectroscopic signatures as a probe of polymorphism remain largely unexplored. Here, chiral phenylalanine...Weak molecular interactions and subtle conformational variations can directly modulate CH bond strength, yet their spectroscopic signatures as a probe of polymorphism remain largely unexplored. Here, chiral phenylalanine in anhydrous Form I, hemihydrated fiber, and hydrogel states were investigated by Raman, IR, and vibrational circular dichroism (VCD) spectroscopy combined with DFT calculations, focusing on the CH stretching region. Isotopic substitution combined with VCD analysis reveals coexistence of gauche (G) and trans (T) conformers in the fiber and hydrogel. The methine CD stretching vibration of the T conformer exhibits a marked blue shift relative to the G- conformer, indicating strengthening of the CH bond induced by close-range electrostatic repulsion from a neighboring NH₃ group. Raman analysis of the hydrogel demonstrates preservation of the local G/T hydrogen-bonded pairing motif and associated π-π interactions despite the absence of long-range crystalline order. These results demonstrate that CH stretching vibrations serve as highly sensitive reporters of weak molecular interactions and local structural organization in condensed phases.
Huo W, Zhang H, Zhang J
… +2 more, Chen H, Zhang Z
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42335701
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In this work, combined electromagnetic "hot spots" generated by densely packed AgNPs with the chemical charge transfer enhancement enabled by the semiconducting performance of NiO, a series of flower-like CFP@NiO@AgNPs h...In this work, combined electromagnetic "hot spots" generated by densely packed AgNPs with the chemical charge transfer enhancement enabled by the semiconducting performance of NiO, a series of flower-like CFP@NiO@AgNPs hierarchical interfaces were fabricated as surface enhancement Raman scattering (SERS) substrates for ultra-sensitive simultaneous detection of multi-fungicide residues. With Rhodamine 6G (R6G) as probe molecule, the CFP@NiO@AgNPs substrate achieved a detection limit 5 × 10 M and a high enhancement factor of 1.08 × 10, along with good uniformity and long-term stability. Notably, the hierarchical CFP@NiO@AgNPs demonstrated excellent molecular enrichment effect and realized the multi-component detection of trace thiabendazole (TBZ) and carbendazim (CBZ) residues in beverages. The detection limits achieved for TBZ and CBZ were 5 × 10 M and 5.23 × 10 M, and was well below regulatory standards respectively. This work provides a portable, sensitive, and dependable SERS sensing platform with significant potential for food safety monitoring and related applications.
Fu X, Yao L, Zhang X
… +7 more, Xiao Y, Gao K, Liu W, Zhang Q, Qi H, Zhang C, Zhao Y
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42335700
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Chlorophyll content (represented by the Soil and Plant Analyzer Development (SPAD) value) and leaf moisture content (LMC) are two key physiological phenotypic traits during wheat growth, and their variations among differ...Chlorophyll content (represented by the Soil and Plant Analyzer Development (SPAD) value) and leaf moisture content (LMC) are two key physiological phenotypic traits during wheat growth, and their variations among different wheat varieties reflect crop growth, stress response, and breeding evaluation. Simultaneous identification of wheat varieties and prediction of SPAD and LMC are therefore important for precision crop monitoring. In this study, hyperspectral imaging was employed to acquire leaf spectral information from four wheat varieties. After spectral preprocessing and outlier screening, 684 valid samples were retained for model development and evaluation. Single-task and multi-task models were constructed for wheat variety classification, SPAD prediction, and LMC prediction using support vector machine (SVM), partial least squares (PLS), convolutional neural network (CNN), and multi-task CNN (MLT-CNN) algorithms. In the MLT-CNN, a shared one-dimensional spectral feature extraction module and three task-specific branches were designed, and equal weight strategy (EWS), adjustable regularization weighted strategy (ARWS), and uncertainty-based weighted strategy (UWS) were compared. The best single-task models achieved a test-set classification accuracy of 0.75, with correlation coefficients (r) of 0.83 for SPAD and 0.84 for LMC. The MLT-CNN with EWS achieved balanced test-set performance across the three tasks, with a classification accuracy of 0.69, an r value of 0.84 for SPAD, and an r value of 0.81 for LMC. Shapley additive explanations (SHAP)-based visualization was further performed for both single-task CNNs and MLT-CNN task branches to identify important wavelengths and interpret shared and task-specific spectral contributions. These results indicate that hyperspectral imaging combined with multi-task learning provides a feasible and interpretable spectroscopic strategy for integrated wheat leaf phenotyping.
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42335699
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Hypochlorite (ClO) and pH are critical factors in environmental safety and physiological processes. Meanwhile, detection of ClO and pH has practical value in optimizing disinfection processes to ensure efficacy and safet...Hypochlorite (ClO) and pH are critical factors in environmental safety and physiological processes. Meanwhile, detection of ClO and pH has practical value in optimizing disinfection processes to ensure efficacy and safety. Herein, a facile dual-functional fluorescence probe was constructed for the determination of ClO and pH by a one-step chemical reaction, utilizing 4-chloro-7-nitrobenzofurazan as the fluorophore and piperazine as the recognition unit. The probe enabled quantitative pH detection from 2.0 to 10.0 via the intramolecular charge transfer (ICT) and photoinduced electron transfer (PET) mechanisms. It can also specifically react with ClO under the alkaline conditions, leading to the cleavage of the CN bond and the release of the piperazine group, suggesting a possible cleavage-mediated selective recognition mechanism. The proposed probe has quick response for pH and ClO detection within 1 min, and has good selectivity and high sensitivity with LOD of 69.8 nM. It was further constructed into a paper sensor integrated with a smartphone, which can achieve smartphone-assisted RGB analysis for on-site detection of pH and ClO in actual environmental water samples. This work can provide a new strategy for fabricating multi-functional fluorescence probes and a promising application for on-site detection of pH and ClO in environmental monitoring.
Qiu Y, Hu M, Liu Y
… +3 more, Jin J, Wang G, Zhao Y
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42335698
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The nitrobenzene trimer anion, NB was generated using a supersonic expansion source in the gas phase. The structure was characterizated using infrared photodissociation (IRPD) spectroscopy of the argon-tagged quantum che...The nitrobenzene trimer anion, NB was generated using a supersonic expansion source in the gas phase. The structure was characterizated using infrared photodissociation (IRPD) spectroscopy of the argon-tagged quantum chemical calculations. The optimized structures of NB and NB(Ar) were categorized into four types of isomers, including CH···O, π-π, and co-contributing (CH···O + π-π, CH···O + CH···π) interactions. Among the isomers stabilized predominantly by CH···O hydrogen bonds, three structural motifs can be distinguished: Y-type, triangular-type, and planar-type isomers. These isomers exhibit pronounced energy differences, with the π-π stacking and CH···π interactions further contributing to their conformational stabilization. Both simulated spectra of planar-type and Y-type isomers exhibit agreement with the experimental spectrum, suggesting the potential coexistence of planar-type and Y-type isomers. The strongest IRPD bands observed at 3019 and 3033 cm are tentatively attributed to the CH···O interactions of the two conformers. The singly occupied molecular orbital (SOMO) reveals that the negative charge distribution in both isomers (a) and (f) are localized on one nitrobenzene unit. This NB unit can be regarded as a negative charge, and it forms an electrostatic attraction with the positive potential region of the benzene ring on the additional NB units to stabilize the structure. More importantly, multiple low-energy isomers stabilized by distinct non-covalent interactions (NCIs) might coexist under the experimental conditions, suggesting a complex conformational landscape that may extend to larger aggregates and condensed phases. These results highlight the importance of considering conformational heterogeneity when interpreting reaction dynamics and non-covalent interactions in molecular assemblies..
Rong Y, Liu Y, Kong F
… +6 more, Zhu H, Fang J, Gao Y, Zhao Q, Hassan MM, Huang J
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42335697
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Porcine epidemic diarrhea virus (PEDV) can cause diarrhea, vomiting, dehydration and high mortality in pigs, resulting in significant economic losses for the swine industry. The current research intelligently converges c...Porcine epidemic diarrhea virus (PEDV) can cause diarrhea, vomiting, dehydration and high mortality in pigs, resulting in significant economic losses for the swine industry. The current research intelligently converges core-shell upconversion nanoparticles (CSUCNPs) and molybdenum disulfide nanosheets modified magnetic nanoparticles (MNPs@MoS) to achieve the diagnosis of PEDV. The scheme employs the inner filter effect via between CSUCNPs and MNPs@MoS. With the existence of PEDV, the aptamers bind to PEDV preferentially and interrupt the IFE, thus leading the recoveries of upconversion fluorescence. Therefore, PEDV can be quantified by the linear curve between fluorescence intensity and logarithm concentration of PEDV at the range of 0.01-10 μg/L. This proposed nanosensor exhibits a satisfied detection of limit as 0.021 μg/L. Importantly, a real sample test was performed and compared with standard method, the results suggested the nanosenor demonstrates excellent accuracy and reproducibility, and has promising application prospects.
Zhang J, Guo J, Qi H
… +3 more, Yu Q, Shi Y, Kong X
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42335696
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A spiking neural network (SNN) based framework was developed for analyzing Raman spectral data. The model was trained to predict the concentration of three pesticides(malachite green, 4-MBA and thiram) by analyzing their...A spiking neural network (SNN) based framework was developed for analyzing Raman spectral data. The model was trained to predict the concentration of three pesticides(malachite green, 4-MBA and thiram) by analyzing their surface-enhanced Raman scattering (SERS) spectra at various concentrations, in which the average prediction accuracy could achieve 95%. The performance was superior than convolutional neural network (CNN) and multilayer perceptron (MLP). The the coefficient of determination (R) value was 0.97 for malachite green detection. Furthermore, this platform was used for detecting thiram from the surface of apple peels with Rat 0.95. The LOD(S/N = 3) of the proposed model for thiram reached 0.37 ppm with recovery value between 96.61%-101.89%. This work demonstrates that the combing SERS with SNN analysis is a feasible, efficient, and precise approach for quantitative detection harmful ingredient from real samples.
Wang LC, Hu JW, Chiu WC
… +2 more, Liu KM, Chen KY
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42330705
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A low-molecular-weight polyethylene glycol (PEG)-modified aniline-indandione conjugate (AI) chemodosimeter was synthesized and compared with its dimethylaniline-indandione precursor. Although the synthesized PEGylated ch...A low-molecular-weight polyethylene glycol (PEG)-modified aniline-indandione conjugate (AI) chemodosimeter was synthesized and compared with its dimethylaniline-indandione precursor. Although the synthesized PEGylated chemodosimeter is highly water soluble, it maintains a high fluorescence quantum yield in the neat film state. When exposed to cyanide in aqueous and solid states, AI exhibits significant changes in color and fluorescence owing to nucleophilic addition, effectively inhibiting the intramolecular charge transfer process. The limit of detection of cyanide by AI is 2.3 × 10 M, aligning with other established cyanide-selective sensors and significantly lower than the World Health Organization's recommended limit of 1.9 × 10 M. We developed simple and affordable paper-based test strips embedding AI, facilitating fast, quantitative, and on-site cyanide detection, visible through color changes and fluorescence. This study demonstrates a practical molecular design strategy for developing water-soluble chemodosimeters tailored for selective cyanide detection.
Zhang Q, Dong G, Li M
… +4 more, Yang R, Zhao R, Yang Z, Ma H
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42330704
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Rapid and accurate detection of total nitrogen (TN) and total phosphorus (TP) in dairy cow slurry is essential for guiding the scientific application of slurry to fields, preventing soil nutrient imbalance and water poll...Rapid and accurate detection of total nitrogen (TN) and total phosphorus (TP) in dairy cow slurry is essential for guiding the scientific application of slurry to fields, preventing soil nutrient imbalance and water pollution, and promoting sustainable agricultural development and resource utilization of slurry. However, the complex composition and high moisture content of slurry, along with the high dimensionality and nonlinear characteristics of its spectral data, pose challenges to accurate and efficient prediction. In this study, near-infrared spectroscopy was combined with partial least squares regression (PLSR), extreme gradient boosting (XGBoost), and deep neural network (DNN) to establish TN and TP prediction models for dairy cow slurry using different spectral preprocessing methods (MSC, SG, and MSC + SG). The optimal preprocessing methods for TN and TP were determined according to model performance. Furthermore, uninformative variable elimination (UVE) and bootstrap soft shrinkage (BOSS) were employed to extract characteristic wavelength variables and construct models, and the performances of different models were compared to identify the optimal one. Results showed that the DNN model achieved the best performance in TN and TP prediction, with R values of 0.92 and 0.75, and RPD values of 3.49 and 2.01, respectively, significantly outperforming PLSR and XGBoost. When using UVE and BOSS, both methods yielded comparable predictive performance; however, BOSS achieved a higher degree of data compression and modeling efficiency, showing greater potential for practical applications. Overall, the BOSS-DNN approach demonstrated remarkable advantages in predicting complex components of dairy slurry and provides a new technical pathway and theoretical foundation for rapid on-site nutrient detection of livestock and poultry slurry.
Godzo H, Deconinck E, Vanhee C
… +4 more, Waeytens J, Geskovski N, Gigopulu O, Brezovska K
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42330703
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Therapeutic peptides represent an important class of biomolecules with great clinical and economic significance, however their structural complexity and susceptibility to degradation pose significant analytical challenge...Therapeutic peptides represent an important class of biomolecules with great clinical and economic significance, however their structural complexity and susceptibility to degradation pose significant analytical challenges. This study aimed to evaluate the applicability of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy in combination with multivariate data analysis as a rapid, non-destructive tool for monitoring structural changes and degradation in formulations containing semaglutide and liraglutide as model compounds. Spectral data allowed the detection of subtle conformational changes, particularly in the amide region I, which is directly related to the secondary structure. The application of principal component analysis (PCA) enabled the identification of clustering patterns and classification of samples under different stress conditions, while the analysis of loading and contribution line plots allowed recognition of the main spectral features contributing most to the variance. Despite the relatively short incubation times and using a dry film approach which may introduce conformational changes, clear changes associated with early and advanced phases of degradation were detected. ATR-FTIR results were complemented by liquid chromatography-high-resolution mass spectrometry (LC-HRMS), showing consistency between the spectroscopic, mass spectrometric and chromatographic data. As demonstrated in this proof-of-concept study, this integrated analytical approach indicates potential for application in stability monitoring, formulation studies, process control, and as part of a multi-analytical strategy for product authentication, particularly when structural alterations are expected. The results confirm the applicability of ATR-FTIR spectroscopy combined with multivariate data analysis as a powerful tool for rapid assessment of the behavior of peptide medicines under stress conditions.
Martini WDS, García-Lojo D, Pastoriza-Santos I
… +2 more, Pérez-Juste J, Pellosi DS
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42330702
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The persistent presence of azo dyes, such as methyl orange (MO), in industrial wastewater represents a major environmental concern due to their chemical stability, toxicity, and the potential formation of hazardous trans...The persistent presence of azo dyes, such as methyl orange (MO), in industrial wastewater represents a major environmental concern due to their chemical stability, toxicity, and the potential formation of hazardous transformation products during treatment processes. Consequently, decolorization alone is not a reliable indicator for environmental remediation. Unlike previous studies that rely on individual techniques, in this work a multimodal analytical approach combining UV-Vis spectroscopy, time-dependent surface-enhanced Raman scattering (SERS), and liquid chromatography-mass spectrometry (LC-MS) is employed to simultaneously monitor chromophore removal and molecular transformation during photocatalytic oxidation. As a photocatalyst model system, ZnO multipods functionalized with Ag nanoparticles (ZnO/Ag nanohybrids) were used under simulated solar irradiation, showing rapid MO degradation. Importantly, time-dependent SERS provides direct insight into the evolution of molecular structure, enabling identification of key processes such as azo-bond cleavage, N-demethylation, and modification of aromatic moieties. Complementary LC-MS analysis enables the separation and identification of intermediate species, including demethylated and hydroxylated species, allowing reconstruction of a multistep oxidative transformation pathway. The combined approach further reveals the temporal evolution and persistence of intermediates, with extended irradiation leading to disappearance of detectable aromatic species. Overall, the integration of SERS and LC-MS provides a robust framework for correlating spectroscopic signatures with molecular-level transformations, offering a comprehensive assessment of photocatalytic processes beyond conventional decolorization metrics.
Wang Z, Li X, Wang Q
… +3 more, Xue X, Wang X, Li JG
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42330701
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Thermochromic luminescent materials with both naked-eye visibility and temperature-sensing potential have become a research focus, but high-temperature thermal quenching still severely limits their practical application....Thermochromic luminescent materials with both naked-eye visibility and temperature-sensing potential have become a research focus, but high-temperature thermal quenching still severely limits their practical application. In this work, a multimodal optical temperature sensor with pronounced anti-thermal quenching behavior is developed based on the negative thermal expansion (NTE) phosphor KMgScMoO: Yb, Ho. The thermal behavior of the F/S and F levels of Ho diverges significantly across the temperature range of 298 to 548 K. The F/S levels show a temperature-dependent decrease in emission intensity, compared to the thermally stable emission characteristic of the F level. Correspondingly, the upconversion (UC) emission shows a gradual chromatic transition from green to red. Based on the NTE characteristics of the material, the observed behavior is attributed to the combined effects of enhanced Yb to Ho energy transfer and the non-radiative relaxation of Ho. Using fluorescence intensity ratio (FIR) and Commission Internationale de l'Éclairage chromaticity coordinate ratio (CIER) technology, excellent temperature sensitivity and low temperature uncertainty are achieved. In addition, benefiting from the broad range thermochromic behavior of the phosphor, its emission color can be reversibly switched during heating and cooling cycles. Finally, a naked-eye readable temperature-sensing platform is constructed, and the temperature evolution of the ceramic heating element is visually demonstrated.
Wang T, Tang Y, Fan Y
… +5 more, Chen M, Yu B, Zhao A, Luo H, Xiao X
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42330700
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With the increasing severity of environmental pollution, the development of efficient and sensitive detection methods for the identification of toxic pollutants in water bodies is of great significance. Herein, we descri...With the increasing severity of environmental pollution, the development of efficient and sensitive detection methods for the identification of toxic pollutants in water bodies is of great significance. Herein, we describe the construction of a supramolecular fluorescent assembly, Q[8]/TIPE-OBr, which was fabricated through host-guest interactions, based on cucurbit[8]uril (Q[8]) as the host and a custom-synthesized tetraphenylethylene imidazole bromide derivative (TIPE-OBr) as the guest molecule. The formation mechanism, structural characteristics, and photophysical properties of the assembly were systematically investigated using UV-Vis absorption spectroscopy, fluorescence spectroscopy, isothermal titration calorimetry (ITC), H NMR spectroscopy, and dynamic light scattering (DLS). The results indicated that the bromophenyl group of TIPE-OBr was encapsulated by Q[8], forming a 2:1 host-guest complex, which significantly enhanced the fluorescence emission of the system (λem = 511 nm). Furthermore, this assembly was applied to detect Fe(CN) and picric acid (PA), showing significant fluorescence quenching with detection limits as low as 1.171 × 10 mol/L and 9.30 × 10 mol/L, respectively. Interference experiments demonstrated its good selectivity and anti-interference ability. Mechanistic studies revealed that the quenching by Fe(CN) is driven by the synergy of electrostatic interaction and inner filter effect, while quenching by PA is governed by charge-transfer interactions. This study offers a promising approach for the detection of two typical pollutants in water.
Qi Y, Cuican Y, Ma W
… +3 more, Luo X, Tang S, Zhang Y
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42330578
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Accurate, non-destructive assessment of wood chemical composition is important for evaluating the quality and utilization of valuable Phoebe woods, but conventional chemical analyses are destructive and cannot describe s...Accurate, non-destructive assessment of wood chemical composition is important for evaluating the quality and utilization of valuable Phoebe woods, but conventional chemical analyses are destructive and cannot describe spatial heterogeneity. In this study, short-wave infrared hyperspectral imaging (SWIR-HSI, 900-1700 nm) was used to predict and map cellulose, hemicellulose, and lignin in Phoebe zhennan and Burma Phoebe. Spectral preprocessing, wavelength selection, and regression modeling strategies were systematically evaluated, and a cascaded CNN-Transformer model was developed to integrate local absorption features with long-range spectral dependencies. Full-spectrum SNV data provided the best input for cellulose prediction, whereas SPA-selected wavelengths improved the prediction of hemicellulose and lignin. The optimal models were SNV-CNN-Transformer for cellulose (R = 0.6784, RPD = 1.7867), SPA-SNV-CNN-Transformer for hemicellulose (R = 0.7719, RPD = 2.1213), and SPA-SNV-CNN-Transformer for lignin (R = 0.7973, RPD = 2.2503). Pixel-level prediction maps further visualized the spatial distribution of the three components across wood cross-sections. These results indicate that SWIR-HSI combined with CNN-Transformer modeling provides a promising approach for non-destructive chemical assessment and spatial characterization of valuable Phoebe woods.
Kavanya S, Antony E, Ganesan N
… +7 more, Paul SPM, Ramalingan C, Prabakaran G, Almansour AI, Kumar RS, Raja PB, Nandhakumar R
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42323925
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A one-step synthesized anthracene-derived chalcone probe (HPA) was characterized by NMR, IR and mass spectrometry and exhibits rapid, selective sensing of Bi ions in DMSO/H₂O (1:1, pH 7.3). The complexation of sensor wit...A one-step synthesized anthracene-derived chalcone probe (HPA) was characterized by NMR, IR and mass spectrometry and exhibits rapid, selective sensing of Bi ions in DMSO/H₂O (1:1, pH 7.3). The complexation of sensor with Bi ions demonstrated a noticeable blueshift accompanied with a turn-on yellow fluorescence response owing to the blockage of excited- state intramolecular proton transfer (ESIPT) and Photoinduced electron transfer (PET) process. The binding stoichiometry and interaction behaviour was revealed through job's plot, IR spectral studies and H NMR titration forming a 1:1 stable HPA+ Bi complex. The limit of detection (LOD) and limit of quantification (LOQ) was determined to be 1.73 nM and 5.76 nM respectively. The probe enables practical Bi detection in food and cosmetic matrices and supports real-world deployment through smartphone readout, test strips, cotton swabs and anti-counterfeiting platforms.
Shoji K, Otsuka M, Tominaga K
… +3 more, Zhang F, Hayashi M, Sasaki T
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42322939
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Galactitol, a hydrogen-bonded sugar alcohol, has attracted considerable attention as a potential organic phase-change material (PCM). In this study, we investigate its thermal expansion and low-frequency lattice vibratio...Galactitol, a hydrogen-bonded sugar alcohol, has attracted considerable attention as a potential organic phase-change material (PCM). In this study, we investigate its thermal expansion and low-frequency lattice vibrations using a combination of temperature-dependent terahertz (THz) spectroscopy and density functional theory (DFT) calculations. This approach enables the characterization of both static and dynamic temperature-dependent changes in the hydrogen-bond network, which plays a crucial role in determining the thermal and phase-transition properties of hydrogen-bonded organic PCMs. Among the observed THz absorption spectra, the lowest-frequency mode exhibited an anomalous blueshift upon heating, whereas all other modes demonstrated a redshift behavior. The quasi-harmonic approximation (QHA) simulations and single-crystal X-ray diffraction (SC-XRD) measurements reveal the pronounced anisotropic thermal expansion of galactitol. It is noteworthy that the QHA captures the qualitative trend of the anomalous blueshift of the lowest-frequency mode through structural changes. The blue-shifting mode is characterized by translational motion primarily along the crystallographic a-axis, with a minor intramolecular OH rocking component contributing to its infrared (IR) activity. This behavior suggests that the O···H-O hydrogen-bond network oriented along the crystallographic c-axis plays a crucial role in the anomalous blueshift.
Hao Y, Zhao Z, Liu X
… +5 more, Wang Y, Bai H, Ai G, Liu X, Li R
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42322938
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This study developed a novel SERS detection platform based on seed-mediated synthesis of core-shell structured Au@Ag NPs. Benefiting from the atomic synergistic effects between the gold core and silver shell, the substra...This study developed a novel SERS detection platform based on seed-mediated synthesis of core-shell structured Au@Ag NPs. Benefiting from the atomic synergistic effects between the gold core and silver shell, the substrate demonstrated exceptional stability, enabling simultaneous dual-target detection of Thiram and Paraquat. Experimental results revealed linear response ranges of 1.0 × 10-1.0 × 10 M (LOD: 6.89 × 10 M) at 1380 cm for Thiram, and 1.0 × 10-1.0 × 10 M (LOD: 9.75 × 10 M) at 840 cm for Paraquat. Spiked recovery rates in apple samples reached 95.6%-102% for Thiram and 95%-98.4% for Paraquat. Quantitative analysis of mixed systems using an MLP model achieved 91% accuracy, 89% recall, 89% F1-score, and 90% precision. This method provides a highly sensitive and reliable technical solution for simultaneous detection of multiple pesticide residues in complex food matrices, demonstrating significant potential for rapid food safety monitoring applications.
Gu B, Hu G, Lu H
… +9 more, Zhu Z, Li Z, He W, Xi N, Chu L, Wei Z, Guo Z, Cao Q, Sun Q
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42322937
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Injury timing estimation and the differentiation between antemortem and postmortem injuries are of considerable importance in forensic practice; however, the discriminatory performance of conventional methods declines ma...Injury timing estimation and the differentiation between antemortem and postmortem injuries are of considerable importance in forensic practice; however, the discriminatory performance of conventional methods declines markedly as decomposition progresses. In this study, we established a rabbit sharp-force injury model, collected full-thickness skin samples at 1-7 days postmortem, and used attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy combined with chemometric methods to analyze the biochemical alterations in superficial injured tissues under natural environmental conditions. The results showed that characteristic bands at 1740 cm, 1650 cm, 1540 cm, and 1080-1030 cm, corresponding primarily to lipid carbonyl, amide I, amide II, and phosphate/carbohydrate-related components, respectively, exhibited pronounced changes with increasing postmortem interval. Principal component analysis (PCA) of the spectral data revealed time-dependent variation trends in the biochemical composition of injured tissues among different groups. Among six machine-learning regression models, partial least squares regression (PLS-R) achieved effective prediction of the postmortem interval, with a highest R(Pred) value of 0.932. Among three classification models, partial least squares discriminant analysis (PLS-DA) showed the best performance for distinguishing abdominal antemortem from postmortem injuries, with an accuracy of 0.976 in the independent prediction set. These findings indicate that ATR-FTIR spectroscopy combined with chemometric analysis can effectively capture dynamic biochemical changes in injured tissues and may provide a rapid and label-free spectroscopic approach for injury timing estimation and the discrimination between antemortem and postmortem injuries.
Spectrochim Acta A Mol Biomol Spectrosc
· 2026 Jun · PMID 42322936
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Organic room-temperature phosphorescent materials, owing to their advantages such as large Stokes shifts and long-lived delayed emission, have significant potential for applications in areas such as luminescent displays...Organic room-temperature phosphorescent materials, owing to their advantages such as large Stokes shifts and long-lived delayed emission, have significant potential for applications in areas such as luminescent displays and information encryption. Currently, host-guest doping remains the mainstream strategy for achieving room-temperature phosphorescence; however, issues such as complex preparation methods and limited emission color range still need to be addressed. In this work, a simple one-step in situ molten host-guest doping strategy is employed to embed polycyclic aromatic hydrocarbon derivatives into a benzophenone matrix. The rigid microenvironment formed upon cooling and crystallization effectively suppresses the non-radiative decay of guest molecules. Additionally, through the modulation of the conjugated structure and substituents of the guest molecules, a controllable tuning of the emission color ranging from cyan to red is achieved. Notably, the composite material PC3A/BPO exhibits a red ultralong afterglow with a lifetime of 231 ms upon 365 nm excitation. Theoretical calculations clearly reveal the intermolecular charge transfer (CT) process within the host-guest system, which lowers the excitation state energy level and enhances spin-orbit coupling, thereby enabling stable and efficient RTP emission. Finally, the obtained host-guest composite materials are successfully applied in multi-level anti-counterfeiting encryption, demonstrating their potential for applications in information security.