- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Detection of E. coli labeled with metal-conjugated antibodies using lateral-flow assay and laser-induced breakdown spectroscopy
摘要： This study explores the adoption of laser-induced breakdown spectroscopy (LIBS) for the analysis of lateral-flow immunoassays (LFIAs). Gold (Au) nanoparticles are standard biomolecular labels among LFIAs, typically detected via colorimetric means. A wide diversity of lanthanide-complexed polymers (LCPs) are also used as immunoassay labels but are inapt for LFIAs due to lab-bound detection instrumentation. This is the first study to show the capability of LIBS to transition LCPs into the realm of LFIAs, and one of the few to apply LIBS to biomolecular label detection in complete immunoassays. Initially, an in-house LIBS system was optimized to detect an Au standard through a process of line selection across acquisition delay times, followed by determining limit of detection (LOD). The optimized LIBS system was applied to Au-labeled Escherichia coli detection on a commercial LFIA; comparison with colorimetric detection yielded similar LODs (1.03E4 and 8.890E3 CFU/mL respectively). Optimization was repeated with lanthanide standards to determine if they were viable alternatives to Au labels. It was found that europium (Eu) and ytterbium (Yb) may be more favorable biomolecular labels than Au. To test whether Eu-complexed polymers conjugated to antibodies could be used as labels in LFIAs, the conjugates were successfully applied to E. coli detection in a modified commercial LFIA. The results suggest interesting opportunities for creating highly multiplexed LFIAs. Multiplexed, sensitive, portable, and rapid LIBS detection of biomolecules concentrated and labeled on LFIAs is highly relevant for applications like food safety, where in-field food contaminant detection is critical.
关键词： Lateral-flow immunoassay,E. coli,Laser-induced breakdown spectroscopy,Lanthanides,Metal-conjugated antibodies
更新于2025-09-16 10:30:52
-
Discrimination of Grape Seeds Using Laser-Induced Breakdown Spectroscopy in Combination with Region Selection and Supervised Classification Methods
摘要： The wine-making industry generates a considerable amount of grape pomace. Grape seeds, as an important part of pomace, are rich in bioactive compounds and can be reutilized to produce useful derivatives. The nutritional properties of grape seeds are largely influenced by the cultivar, which calls for effective identification. In the present work, the spectral profiles of grape seeds belonging to three different cultivars were collected by laser-induced breakdown spectroscopy (LIBS). Three conventional supervised classification methods and a deep learning method, a one-dimensional convolutional neural network (CNN), were applied to establish discriminant models to explore the relationship between spectral responses and cultivar information. Interval partial least squares (iPLS) algorithm was successfully used to extract the spectral region (402.74–426.87 nm) relevant for elemental composition in grape seeds. By comparing the discriminant models based on the full spectra and the selected spectral regions, the CNN model based on the full spectra achieved the optimal overall performance, with classification accuracy of 100% and 96.7% for the calibration and prediction sets, respectively. This work demonstrated the reliability of LIBS as a rapid and accurate approach for identifying grape seeds and will assist in the utilization of certain genotypes with desirable nutritional properties essential for production rather than their being discarded as waste.
关键词： grape seed,laser-induced breakdown spectroscopy,supervised classification,region selection,deep learning
更新于2025-09-16 10:30:52
-
Ultrafast Elemental Mapping of Platinum Group Elements and Mineral Identification in Platinum-Palladium Ore Using Laser Induced Breakdown Spectroscopy
摘要： This paper demonstrates the capability of performing an ultrafast chemical mapping of drill cores collected from a platinum/palladium mine using laser‐induced breakdown spectroscopy (LIBS). A scan of 40 mm × 30 mm was performed, using a commercial LIBS analyzer, onto the flat surface of a drill core with a scanning speed of 1000 Hz, and a spatial resolution of 50 μm, in about 8 min. Maps of the scanned areas for seven chemical elements (platinum, palladium, nickel, copper, iron, silicon, and magnesium), as well as a single map including the seven elements altogether, were then generated using the proprietary software integrated into the LIBS analyzer. Based on the latter image, seven minerals were identified using the principal component analysis (PCA) and correlations with the elemental maps.
关键词： laser induced breakdown spectroscopy (LIBS),mineral identification,platinum‐group elements (PGE),principal component analysis (PCA),scanning speed at 1000 Hz
更新于2025-09-16 10:30:52
-
Analysis of Pollution in High Voltage Insulators via Laser-Induced Breakdown Spectroscopy
摘要： Surface pollution deposition in a high voltage surface can reduce the surface ?ashover voltage, which is considered to be a serious accident in the transmission of electric power for the high conductivity of pollution in wet weather, such as rain or fog. Accordingly, a rapid and accurate online pollution detection method is of great importance for monitoring the safe status of transmission lines. Usually, to detect the equivalent salt deposit density (ESDD) and non-soluble deposit density (NSDD), the pollution should be collected when power cut o? and bring back to lab, time-consuming, low accuracy and unable to meet the online detection. Laser-induced breakdown spectroscopy (LIBS) shows the highest potential for achieving online pollution detection, but its application in high voltage electrical engineering has only just begun to be examined. In this study, a LIBS method for quantitatively detecting the compositions of pollutions on the insulators was investigated, and the spectral characteristics of a natural pollution sample were examined. The energy spectra and LIBS analysis results were compared. LIBS was shown to detect pollution elements that were not detected by conventional energy spectroscopy and had an improved capacity to determine pollution composition. Furthermore, the e?ects of parameters, such as laser energy intensity and delay time, were investigated for arti?cial pollutions. Increasing the laser energy intensity and selecting a suitable delay time could enhance the precision and relative spectral intensities of the elements. Additionally, reducing the particle size and increasing the density achieved the same results.
关键词： quantitatively analysis,surface pollution,high voltage insulators,laser-induced breakdown spectroscopy
更新于2025-09-16 10:30:52
-
Picosecond laser ablation and depth profile of Cu(In, Ga)Se2 thin film layer
摘要： Laser ablation based on picosecond laser was used to achieve the micro-analysis of Cu(In, Ga)Se2 (CIGS) thin film with the ablation crater diameter of 50 μm and the ablation crater central depth of 93 ± 13 nm. We achieved the depth profile of CIGS thin film with different laser shot number. The evolutions of spectral lines intensities of Ca from glass substrate and Ga and In from CIGS thin film layer, and intensity ratios of Ca/Ga and Ca/In could exhibit the change of the ablation volume, which could estimate the thin film thickness of single CIGS thin film layer. The average plasma temperature was calculated to be about 5243 ± 100 K, and the average electron density was calculated to be about 4.5×1016 cm?3. It is shown that our experimental setup is suitable to achieve a precise control and monitor the element compositions in each CIGS thin film layer in the research and in the production of CIGS solar cells.
关键词： Ablation morphology,Electron density,Cu(In, Ga)Se2 thin film,Picosecond laser induced breakdown spectroscopy,Plasma temperature
更新于2025-09-16 10:30:52
-
Application of Scikit and Keras Libraries for the Classification of Iron Ore Data Acquired by Laser-Induced Breakdown Spectroscopy (LIBS)
摘要： Due to the complexity of, and low accuracy in, iron ore classification, a method of Laser‐Induced Breakdown Spectroscopy (LIBS) combined with machine learning is proposed. In the research, we collected LIBS spectra of 10 iron ore samples. At the beginning, principal component analysis algorithm was employed to reduce the dimensionality of spectral data, then we applied k‐nearest neighbor model, neural network model, and support vector machine model to the classification. The results showed that the accuracy of three models were 82.96%, 93.33%, and 94.07% respectively. The results also demonstrated that LIBS with machine learning model exhibits an excellent classification performance. Therefore, LIBS technique combined with machine learning can achieve a rapid, precise classification of iron ores, and can provide a completely new method for iron ores’ selection in the metallurgical industry.
关键词： machine learning,laser‐induced breakdown spectroscopy,iron ore,classification
更新于2025-09-16 10:30:52
-
High-throughput analysis of single particles by micro laser induced breakdown spectroscopy
摘要： Multi-elemental analysis of particulate matters is highly desirable for the identification of their emission sources. However, the traditional techniques for single particle analysis usually require time-consuming sample preparation procedures. We report here a system that combines bright-field microscopy with laser induced breakdown spectroscopy (LIBS), allowing rapid and multi-elemental analysis of single particles. The improved throughput of the system was benefited from the use of ultra-thin polyethylene films for particle immobilization such that their spectra were collected successively. The simple composition of the films avoided their interferences in the particles’ LIBS spectra. Moreover, the small thickness of the films allowed their rapid vaporization during laser ablation such that the plasma emissions from the particles were not quenched by their substrates. The performances of the system were demonstrated by studying the heterogeneity in particles’ compositions and discriminating dust particles with very similar chemicals, suggesting that it is a promising tool for environmental risk assessment.
关键词： single particles,Laser induced breakdown spectroscopy,high-throughput
更新于2025-09-16 10:30:52
-
Laser-induced breakdown spectroscopy for food authentication
摘要： With the globalisation of food markets, food authentication has become a significant concern worldwide to ensure food safety and to avoid origin and quality fraud. A multi-elemental fingerprint is a powerful tool for detection of adulterants and geographical origin of foods. Laser-induced breakdown spectroscopy (LIBS) is a promising technique that can provide a mineral fingerprint of food products. LIBS allows a rapid, high-throughput, micro-destructive and multi-elemental analysis of a wide range of samples type. It has already been demonstrated by several authors that LIBS can be successfully used for food authentication. Although LIBS shows excellent potential for at-line or portable applications, improvement in sensitivity of trace elements detection, sample preparation, data analysis and instrument miniaturisation are needed.
关键词： LIBS,Laser-induced breakdown spectroscopy,multi-elemental analysis,food authentication,fraud detection
更新于2025-09-16 10:30:52
-
Investigation of excitation interference in laser-induced breakdown spectroscopy assisted with laser-induced fluorescence for chromium determination in low-alloy steels
摘要： Chromium determination in steels suffered from excitation interference in laser-induced breakdown spectroscopy assisted with laser-induced fluorescence (LIBS-LIF). In this work, excitation interference between target chromium atoms and matrix iron atoms was investigated in detail. Relative absorption strength (RAS) of chromium and iron was mathematically deduced and utilized to estimate the excitation interference theoretically. Standard calibration curves of LIBS and LIBS-LIF for chromium determination in low-alloy steels were experimentally established. The chromium line 359.35 nm with less interference in the RAS map provided better analytical performance (slope of 1.99 ×10 5 counts/ wt%, detection limit of 8.64 μg g ? 1 , R 2 of 0.992, average RSD of 2.89%), in accordance with the theoretical estimation. This work realized sensitive and accurate determination of trace chromium in low-alloy steels, even influenced by excitation interference. An effective estimation method was provided for evaluating excitation interference to choose a suitable excitation line.
关键词： Laser-induced fluorescence,Steel,Excitation interference,Chromium,Laser-induced breakdown spectroscopy
更新于2025-09-12 10:27:22
-
[IEEE 2019 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Saint-Petersburg, Russia (2019.6.3-2019.6.7)] 2019 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Analysis of Hpht Diamonds by Laser-Induced Breakdown Spectroscopy
摘要： The analysis of sectoral nitrogen-containing HPHT diamonds by the method of laser-induced breakdown spectroscopy was performed. The possibility of detecting changes in structural bonds and the impurity composition under conditions of laser- induced graphitization of the surface was studied. It was found that the plasma spectra of transition states of the surface during the process of laser-induced graphitization are also very important for analysis and can help identification of diamonds. the Identification of diamonds can occur both based on detecting differences in the content of H, O, N impurities, and detecting differences in the structural disorder of carbon bonds, particularly in the relative change in the number of C=C bonds. All these differences may be a consequence of either technological differences in the history of diamond synthesis, or the presence of additional post-growth diamond processing, or with the presence of the multisectoral structure of the test sample
关键词： HPHT diamonds,laser-induced breakdown spectroscopy,laser-induced graphitization
更新于2025-09-12 10:27:22