Jin, SilaJung, Young MeePark, EungyeongGuo, Shuang...
8页
查看更多>>摘要：Recently, the degradation and detection of 2,4-dinitrotoluene (2,4-DNT) capable of producing 2,4,6-trinitrotoluene (TNT) for environmental and human health risks have been developed. We prepared photoresponsive Au-decorated Fe3O4@TiO2 nanoparticles (Fe3O4@TiO2-Au NPs) under sunlight simulated Xe lamp irradiation. The photodegradation process of 2,4-DNT by Fe3O4@TiO2-Au NPs was successfully monitored by surface-enhanced Raman scattering (SERS). Since SERS monitoring shows intrinsic information about the molecular structure, it was possible to predict the photodegradation of 2,4-DNT. The 2,4-DNT photodegradation mechanism based on two-dimensional correlation spectroscopy (2D-COS), which provides very beneficial information for a deeper understanding of systems, has been identified. We confirmed that Fe3O4@TiO2-Au NPs can be widely used in organic pollutant degradation under sunlight. Furthermore, the combination of SERS based process monitoring and 2D-COS can be a convincing analytical technique for photodegradation studies of organic pollutants. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The development of high-selective chemosensors for trace Al3+ detection in the ecosystem is crucially importance due to its detrimental effects. In this work, a simple Schiff-base fluorescent probe NPP derived from naphthalimide and picolinohydrazide was rationally designed and prepared for efficient detection of Al3+. NPP exhibited prominent sensing behaviors toward Al3+ with low detection limit (LOD) (39 nM), rapid response time (1 min), strong binding affinity (4.02 x 10(4)), good anti-interference characteristics and visual detection. Binding ratio of NPP-Al3+ complex was determined to be 1:1 by Job's plot analysis. In addition, the chelation mechanism of NPP with Al3+ ions was proposed and substantiated by the density functional theory (DFT) and time-dependent density functional theory (TD-DFT), IR spectrum and H-1 NMR titration experiments. Furthermore, this "signal-on" probe NPP was efficiently utilized as a promising indicator for Al3+ detection in environmental and biological samples. (C) 2022 Elsevier B.V. All rights reserved.
Stinghen Garcia Lonni, Audrey AlesandraDahmer, DeboraPacheco da Costa, Isabela AlmeidaDiCiaula, Maria Cristina...
11页
查看更多>>摘要：Emulsion systems have been a breakthrough in cosmetic products, providing performance and effectiveness of products that use this technological strategy for drug delivery systems. In this sense, the microemulsion of the multiple emulsion W/O/W type containing a standardized extract of Trichilia catigua with high levels of polyphenols and antioxidants has great potential for cosmetic use. The aim of this study was to evaluate the formulations safety through the analysis of toxicity, comedogenicity, and histopathology in rabbits and apply the Phase-Resolved Photoacoustic Spectroscopy method to determine the formulation percutaneous penetration through the skin. The ex vivo experiments were performed in the ears of albino New Zealand rabbits treated twice a day for 14 days. The results of histological, hematological, and blood chemistry showed that the formulations are safe. Histopathological analysis showed no tissue reaction in any of the analyzed organs (liver and kidneys), confirming the absence of toxicity. Histological analysis showed that the formulations with extract of T. catigua demonstrated mild-moderately comedogenic and acanthosis compared to the control group. Inflammatory reactions, erythema, and desquamation were not observed in treated and controls animals. The phase-resolved photoacoustic spectroscopy method showed the penetration of the developed formulations throughout the rabbit's skin, identifying their absorption bands at the dermal side of the skin. In conclusion, the results of this study provide a step towards the application of the developed natural antioxidant encapsulated in a multiple microemulsion for skincare, concerned with the physical, chemical, and biological properties of the formulation. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：A lysosome-targeting ratiometric fluorescent probe was synthesized for detecting sulfite based on sulfite-triggered nucleophilic addition reaction. Due to the specific reaction, the fluorescence intensity ratio (I-530/I-390) of the probe in an almost aqueous solution (0.5% DMSO) changed significantly after the addition of HSO3, corresponding to the change in the fluorescence color of the solution from green to blue. The recognition was conducted using high-resolution mass spectrometry, proton nuclear magnetic resonance, and density functional theory calculations. The fluorescent probe could be utilized to quantitatively monitor HSO3 in lysosomes of living C6 glioma cells and real-water samples. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Viscosity and hypochlorite (OCl-) play an important role in biological activities and may cause negative effects at abnormal levels. In this study, a novel lysosome-target fluorescent probe BDHA was obtained based on a benzothiazole derivative. Probe BDHA showed linear ranges of detection for viscosity from 1.62 cP to 851.6 cP with a fluorescent turn-on response. It can also be used as a sensor for OCl- with a turn-off response and showed a good linear range from 0 to 390 mu M, with the detection limit calculated to be 2.8 mu M. Moreover, BDHA can also be used to image viscosity and OCl- levels in HeLa cells and zebrafish, owing to its excellent optical properties. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：In this study, convolutional neural network based on Gramian angular field (GAF-CNN) was firstly proposed. The 1-D Raman spectral data was converted into images and used for predicting the biochemical value of blood glucose. 106 sets of blood spectrums were acquired by Fourier transform (FT) Raman spectroscopy. Spectral data ranging from 800 cm(-1) to 1800 cm(-1) were selected for quantitative analysis of the blood glucose. Data augmentation was used to train neural networks and normalize the Raman spectra. And, we applied principal component analysis (PCA) for dimension reduction and information extraction. The root mean squared error of prediction (RMSEP) are 0.06570 (GADF) and 0.06774 (GASF), the determination coefficient of prediction (R-2) are 0.99929 (GADF) and 0.99925 (GASF), and the residual predictive deviation of prediction (RPD) are 37.56324 (GADF) and 36.43362 (GASF). GAF-CNN model performed better for predicting of glucose concentration. The GAF-CNN model can be used to establish a calibration model to predict blood glucose concentration. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Surface-enhanced Raman spectroscopy (SERS) is an ultra-sensitive analytical tool that can effectively detect and identify molecules by their unique vibrational fingerprints. Development of SERS substrates with good stability, high sensitivity and reproducibility is still a big challenge in practical applications. Recently, 2D materials/metallic hybrid SERS substrates provide a new prospect to improve the SERS performance. Here, we obtain a monolayer MoS2 covered silver nanoparticle (AgNP) array as a high-performance SERS substrate. Annealing temperature-dependent SERS signals on the hybrid substrate have been explored. The optimum SERS performance was obtained at 290 t (the detection limit of 10(13) M for Rhodamine 6G and the corresponding SERS enhancement factor of 8.3 x 10(9)), which is attributed to the better contact between AgNPs and MoS2 and the uniform AgNPs with appropriate particle sizes. The prepared MoS2/AgNPs hybrid substrates also have been utilized to detect various molecules, which demonstrates a great potential for applications in food safety and biochemical environmental detection. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Multi-source spectroscopy is increasingly applied in water contaminant analysis, and general existing spectral features are based on direct mathematical statistics rather than revealing inherent connection between multisource spectra, which has restricted the accuracy and robustness performance. Here in, a novel method is proposed and it is based on the inherent connection between fluorescence and absorption spectra, which can reflect deeper information than conventional methods. The relevant theory was analyzed based on energy level transition and the symmetry between absorption and fluorescence spectra, and then three features were extracted related to internal molecular properties and dependent on two sources of spectral information simultaneously. The three features include the width of the fluorescence emission peak, Stokes shift and symmetry axis between absorption peak and fluorescent emission peak, that correspond to bandwidth of the ground state, vibrational relaxations and conjugate systems respectively. Their significant change of values in monitoring can reflect richer and deeper information in pollution events for contamination tracing and subsequent processing, such as the category, common properties and functional groups of contaminants. The effectiveness of this feature extraction method was assessed by conducting experiments with sample mixtures of typical chemicals and four real water samples. The results highlight the potential of these features in water pollution early warning and contaminant analysis with richer information and stronger robustness. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Aflatoxin B-1 (AFB(1)) is the most widely distributed, most toxic, and most harmful, and it is widely present in moldy grains. This study proposes a new method for quantitative and rapid determination of the AFB(1) content in maize based on Raman spectroscopy. The Raman spectra of maize samples with different mildew degrees were collected by a portable laser Raman spectroscopy system. Three different spectral selection methods, which were bootstrapping soft shrinkage (BOSS), variable combination population analysis (VCPA) and competitive adaptive reweighted sampling (CARS), were applied to optimize the characteristic wavelength variables of the pretreated Raman spectra. The support vector machine (SVM) detection models based on different optimized characteristic wavelength variables were established, and the results of each detection model were compared. The results obtained showed that the performance of the SVM models established by optimized features was significantly better than the performance of the SVM model built by full-spectrum data. Among them, the SVM model based on the characteristic wavelength variables optimized by the CARS method had the best performance, and its root mean square error of prediction (RMSEP) was 3.5377 mu g.kg(-1), the determination coefficient of prediction (R-P(2)) was 0.9715, and the relative prediction deviation (RPD) was 5.8258. The overall results reveal that the rapid quantitative detection of the AFB(1) in maize by Raman spectroscopy has a promising application prospect. In addition, the implementation of the characteristic wavelength optimization of Raman spectra in the model calibration process can effectively improve the detection accuracy of chemometric models. (C) 2022 Elsevier B.V. All rights reserved.
Robert-Peillard, FabienEl Mouchtari, El MountassirBonne, DamienHumbel, Stephane...
10页
查看更多>>摘要：A new microplate analytical procedure is described for the determination of nickel (Ni2+) ions in natural water samples. A lophine analogue fluorescent sensor was synthesized and a spectral study showed a selective fluorescence quenching effect of chemical sensor by Ni2+ under optimized conditions. Density functional theory (DFT) calculations confirmed the formation of a Ni(II)L-3 complex obtained by the Job plot. The calculations showed that the fluorescence emission peak of L collapses due to the distortion of L in the complex. The simple and fast microplate procedure allowed us to quantify Ni2+ with a linear response from 1.6 to 40 mu g L-1 and a quantification limit of 5.4 mu g L-1 without the need of a preconcentration step. The optimized procedure using high-throughput microplate assay has been applied for the determination of Ni2+ in natural water samples with good analytical performances. (C) 2022 Elsevier B.V. All rights reserved.
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