scholarly journals "Electronic tongue" based on electrodes modified with polyarylenephthalides for recognition of model solutions of tryptophan

2020 ◽  
Vol 64 (11) ◽  
pp. 18-27
Author(s):  
Yulia A. Yarkaeva ◽  
◽  
Elena V. Shestakova ◽  
Marat I. Nazyrov ◽  
Rufina A. Zilberg ◽  
...  
Keyword(s):  
Electronic Tongue ◽  
Modified Electrodes ◽  
Principal Component ◽  
Sensor System ◽  
Sensor Systems ◽  
Cross Sensitivity ◽  
Glassy Carbon Electrodes ◽  
Auxiliary Component ◽  
Model Solutions ◽  
Almost All

The effect of auxiliary substances in the composition of the dosage form (sucrose, lactose, talc and starch) on the voltammetric registration of tryptophan using two- and threesensor systems such as "electronic tongue" based on glassy carbon electrodes modified with polyarylenephthalides was studied. For the subsequent chemometric processing of the obtained data, the principal component analysis and soft independent modeling of class analogies were used. It has been shown that electrodes modified with various polyarylenephthalides have cross-sensitivity to four model solutions of tryptophan, each of which contains a certain auxiliary component. When the modified electrodes are used separately, the analyzed model solutions of tryptophan form clusters on the score plots of PCA that intersect with each other, which does not allow them to be reliably recognized. However, the combination of modified electrodes into two- and three-sensor systems due to cross-sensitivity makes it possible to obtain the PCA score plots, in which clusters of samples of model solutions of tryptophan intersect less or do not intersect at all, and, therefore, to recognize them with a high probability. In almost all cases of using two- and three-sensor systems, the classification sensitivity is 100%. When using modified electrodes separately, the specificity of the classification varies from 20 to 100%, when using two-sensor systems – from 50 to 100%. The specificity of the classification when using a three-sensor system is not less than 90%. The proposed sensor system, after additional studies, can be used to recognize medicines containing the same active substance, but different auxiliary components, and will also allow detecting the presence of impurities in medicines.

scholarly journals Discrimination of Milks with a Multisensor System Based on Layer-by-Layer Films

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2716 ◽  
Author(s):  
Coral Salvo-Comino ◽  
Celia García-Hernández ◽  
Cristina García-Cabezón ◽  
Maria Rodríguez-Méndez
Keyword(s):  
Copper Phthalocyanine ◽  
Electronic Tongue ◽  
Principal Component ◽  
Sensor System ◽  
Galactose Oxidase ◽  
Milk Analysis ◽  
Layer By Layer ◽  
Additional Information ◽  
Milk Samples ◽  
Calibration Models

A nanostructured electrochemical bi-sensor system for the analysis of milks has been developed using the layer-by-layer technique. The non-enzymatic sensor [CHI+IL/CuPcS]2, is a layered material containing a negative film of the anionic sulfonated copper phthalocyanine (CuPcS) acting as electrocatalytic material, and a cationic layer containing a mixture of an ionic liquid (IL) (1-butyl-3-methylimidazolium tetrafluoroborate) that enhances the conductivity, and chitosan (CHI), that facilitates the enzyme immobilization. The biosensor ([CHI+IL/CuPcS]2-GAO) results from the immobilization of galactose oxidase on the top of the LbL layers. FTIR, UV–vis, and AFM have confirmed the proposed structure and cyclic voltammetry has demonstrated the amplification caused by the combination of materials in the film. Sensors have been combined to form an electronic tongue for milk analysis. Principal component analysis has revealed the ability of the sensor system to discriminate between milk samples with different lactose content. Using a PLS-1 calibration models, correlations have been found between the voltammetric signals and chemical parameters measured by classical methods. PLS-1 models provide excellent correlations with lactose content. Additional information about other components, such as fats, proteins, and acidity, can also be obtained. The method developed is simple, and the short response time permits its use in assaying milk samples online.

scholarly journals Multisensor System Based on Layer by Layer Films. Discrimination of Milks

2018 ◽  
Author(s):  
Coral Salvo-Comino ◽  
Celia Garcia-Hernandez ◽  
Cristina Garcia-Cabezon ◽  
Maria Luz Rodriguez-Mendez
Keyword(s):  
Copper Phthalocyanine ◽  
Electronic Tongue ◽  
Principal Component ◽  
Sensor System ◽  
Galactose Oxidase ◽  
Milk Analysis ◽  
Layer By Layer ◽  
Additional Information ◽  
Milk Samples ◽  
On Line

A nanostructured electrochemical bi-sensor system for analysis of milks has been developed using the Layer by Layer technique. The non-enzymatic sensor [CHI+IL/CuPcS]2, is a layered material containing a negative film of the anionic sulfonated copper phthalocyanine (CuPcS) acting as electrocatalytic material, and a cationic layer containing a mixture of an ionic liquid (IL) (1-butyl-3-methylimidazolium tetrafluoroborate) that enhances the conductivity and chitosan (CHI) that facilitates the enzyme immobilization. The biosensor ([CHI+IL/CuPcS]2-GAO) results from the immobilization of galactose oxidase on the top of the LbL layers. FTIR, UV-vis and AFM have confirmed the proposed structure and cyclic voltammetry has demonstrated the amplification caused by the combination of materials in the film. Sensors have been combined to form an electronic tongue for milk analysis. Principal Component Analysis has revealed the ability of the sensor system to discriminate between milk samples with different lactose content. Using PLS-1 calibration models, correlations have been found between the voltammetric signals and chemical parameters measured by classical methods. PLS-1 models provide excellent correlations with lactose content. Additional information about other components such as fats, proteins and acidity can also be obtained. The method developed is simple and the short response time permits its use in assaying milk samples on-line.

scholarly journals Patch-Type Vibration Visualization (PVV) Sensor System Based on Triboelectric Effect

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3976
Author(s):  
Sun Jin Kim ◽  
Myeong-Lok Seol ◽  
Byun-Young Chung ◽  
Dae-Sic Jang ◽  
Jonghwan Kim ◽  
...  
Keyword(s):  
Signal Processing ◽  
Low Power ◽  
Nuclear Power ◽  
Power Plants ◽  
Computing System ◽  
Sensor System ◽  
Wireless Sensor ◽  
Sensor Systems ◽  
Patch Type ◽  
Triboelectric Effect

Self-powered wireless sensor systems have emerged as an important topic for condition monitoring in nuclear power plants. However, commercial wireless sensor systems still cannot be fully self-sustainable due to the high power consumption caused by excessive signal processing in a mini-electronic computing system. In this sense, it is essential not only to integrate the sensor system with energy-harvesting devices but also to develop simple data processing methods for low power schemes. In this paper, we report a patch-type vibration visualization (PVV) sensor system based on the triboelectric effect and a visualization technique for self-sustainable operation. The PVV sensor system composed of a polyethylene terephthalate (PET)/Al/LCD screen directly converts the triboelectric signal into an informative black pattern on the LCD screen without excessive signal processing, enabling extremely low power operation. In addition, a proposed image processing method reconverts the black patterns to frequency and acceleration values through a remote-control camera. With these simple signal-to-pattern conversion and pattern-to-data reconversion techniques, a vibration visualization sensor network has successfully been demonstrated.

scholarly journals Magnetron Sputtering Thin Films as Tool to Detect Triclosan in Infant Formula Powder: Electronic Tongue Approach

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 336
Author(s):  
Cátia Magro ◽  
Margarida Sardinha ◽  
Paulo A. Ribeiro ◽  
Maria Raposo ◽  
Susana Sério
Keyword(s):  
Thin Films ◽  
Infant Formula ◽  
Tap Water ◽  
Milk Powder ◽  
Electronic Tongue ◽  
Principal Component ◽  
Formula Milk ◽  
Straight Line ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Triclosan (TCS) is being detected in breast milk and in infants of puerperal women. The harmful effects caused by this compound on living beings are now critical and thus it is pivotal find new tools to TCS monitoring. In the present study, an electronic tongue (e-tongue) device comprising an array of sputtered thin films based on Multi-Walled Carbon Nanotubes and titanium dioxide was developed to identify TCS concentrations, from 10−15 to 10−5 M, in both water and milk-based solutions. Impedance spectroscopy was used for device signal transducing and data was analyzed by principal component analysis (PCA). The e-tongue revealed to be able to distinguish water from milk-based matrices through the two Principal Components (PC1 and PC2), which represented 67.3% of the total variance. The PC1 values of infant formula milk powder prepared with tap water (MT) or mineral water (MMW) follows a similar exponential decay curve when plotted with the logarithm of concentration. Therefore, considering the TCS concentration range between 1015 and 10−9 M, the PC1 values are fitted by a straight line and values of −1.9 ± 0.2 and of 7.6 × 10−16 M were calculated for the sensor sensitivity and sensor resolution, respectively. Additionally, a strong correlation (R = 0.96) between MT and MMW PC1 data was found. These results have shown that the proposed device corresponds to a promisor method for the detection of TCS in milk-based solutions.

scholarly journals Electrochemical Glucose Oxidation Using Glassy Carbon Electrodes Modified with Au-Ag Nanoparticles: Influence of Ag Content

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Nancy Gabriela García-Morales ◽  
Luis Alfonso García-Cerda ◽  
Bertha Alicia Puente-Urbina ◽  
Leonor María Blanco-Jerez ◽  
René Antaño-López ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Electrode Surface ◽  
Glucose Oxidation ◽  
Modified Electrodes ◽  
Alkaline Media ◽  
Carbon Electrodes ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Glassy Carbon Electrodes ◽  
Transmission Electron

This paper describes the application of glassy carbon modified electrodes bearing Aux-Agynanoparticles to catalyze the electrochemical oxidation of glucose. In particular, the paper shows the influence of the Ag content on this oxidation process. A simple method was applied to prepare the nanoparticles, which were characterized by transmission electron microscopy, Ultraviolet-Visible spectroscopy, X-ray diffraction spectroscopy, and cyclic voltammetry. These nanoparticles were used to modify glassy carbon electrodes. The effectiveness of these electrodes for electrochemical glucose oxidation was evaluated. The modified glassy carbon electrodes are highly sensitive to glucose oxidation in alkaline media, which could be attributed to the presence of Aux-Agynanoparticles on the electrode surface. The voltammetric results suggest that the glucose oxidation speed is controlled by the glucose diffusion to the electrode surface. These results also show that the catalytic activity of the electrodes depends on the Ag content of the nanoparticles. Best results were obtained for the Au80-Ag20nanoparticles modified electrode. This electrode could be used for Gluconic acid (GA) production.

scholarly journals Genetic diversity analysis of parental lines for hybrid development in rice (Oryza sativa L.)

2013 ◽  
Vol 37 (4) ◽  
pp. 617-624 ◽  
Author(s):  
MJ Hasan ◽  
Umma Kulsum ◽  
MMH Rahman ◽  
MMH Chowdhury ◽  
AZMKA Chowdhury
Keyword(s):  
Genetic Diversity ◽  
Oryza Sativa L ◽  
Principal Component ◽  
Mean Value ◽  
Cluster Distance ◽  
Parental Lines ◽  
Almost All ◽  
Yield Maximization ◽  
Hybrid Development ◽  
Panicle Weight

Genetic divergence of 40 parental lines comprising 30 restorer and 10 maintainer lines were studied through Mohalanobis's D2 and principal component analysis for eleven characters. Genotypes were grouped into five different clusters. Cluster V comprised maximum number of genotypes (thirteen) followed by cluster I and II. The inter-cluster distance was maximum between clusters I and V (13.495) indicating wide genetic diversity between these two clusters followed by the distance between cluster I and 11 (9.489), cluster IV, and cluster V (8.969) and cluster I and cluster III (8.039). The minimum inter-cluster distance was observed between cluster II and cluster III (3.034) followed by cluster 111 and cluster IV (3.834) and cluster II and cluster V (4.945) indicating that the genotypes of these clusters were genetically close. The intra cluster distance in the entire five clusters was more or less low which indicated that the genotypes within the same cluster were closely related. Among the characters panicle weight contributed most for divergence in the studied parental lines. Difference in cluster means existed for almost all the characters studied. Highest mean value for number of effective tillers (7.8), days to 50% flowering (95.5), panicles/m2 (192.6), panicle weight (2.9), spikelet fertility (84.8), number of grains/panicle (177.8), days to maturity (123.6), and grain yield/plot (1065.5) were observed in cluster I indicated the parental lines fallen in this cluster having the genetic potentiality to contribute better for yield maximization of hybrid rice. DOI: http://dx.doi.org/10.3329/bjar.v37i4.14386 Bangladesh J. Agril. Res. 37(4): 617-624, December 2012

scholarly journals Influence of wine components on pellicle formation by pellicle-forming yeasts

OENO One ◽  
2021 ◽  
Vol 55 (3) ◽  
pp. 363-375
Author(s):  
Fumie Watanabe-Saito ◽  
Youji Nakagawa ◽  
Munekazu Kishimoto ◽  
Masashi Hisamoto ◽  
Tohru Okuda
Keyword(s):  
Red Wine ◽  
Principal Component ◽  
Wine Grape ◽  
Pellicle Formation ◽  
Grape Cultivar ◽  
The Mean ◽  
Almost All ◽  
Mean Concentration ◽  
Muscat Bailey A ◽  
Grape Cultivars

This study aimed to clarify differences in susceptibility to red wine pellicle formation by pellicle-forming yeasts between two wine grape cultivars and to investigate wine components affecting pellicle formation. Twenty wines each of Muscat Bailey A (MBA) and Merlot (MR), the major grape cultivars of Japanese red wine, were used. Pellicle formation occurred more often in MBA wines than in MR wines, and almost all MBA wine surfaces were covered with pellicle after incubation for five days. Principal component analysis revealed the relationships between pellicle formation and the concentrations of ethanol, phenolics and tannins. The mean concentration of tannins in the pellicle MR wines (436 mg/L) was significantly lower than that in the non-pellicle MR wines (660 mg/L). Furthermore, the mean concentration of tannins in MBA wines (139 mg/L) was also significantly lower than that in MR wines (570 mg/L). Wine grape cultivar having a low concentration of tannins may be highly susceptible to pellicle formation by pellicle-forming yeasts during winemaking.

Positional Differences in Elite Basketball: Selecting Appropriate Training-Load Measures

2018 ◽  
Vol 13 (7) ◽  
pp. 947-952 ◽  
Author(s):  
Luka Svilar ◽  
Julen Castellano ◽  
Igor Jukic ◽  
David Casamichana
Keyword(s):  
Principal Components ◽  
Perceived Exertion ◽  
Principal Component ◽  
Training Load ◽  
Rating Of Perceived Exertion ◽  
Change Of Direction ◽  
External Variables ◽  
Load Monitoring ◽  
External Training ◽  
Almost All

Purpose: To study the structure of interrelationships among external-training-load measures and how these vary among different positions in elite basketball. Methods: Eight external variables of jumping (JUMP), acceleration (ACC), deceleration (DEC), and change of direction (COD) and 2 internal-load variables (rating of perceived exertion [RPE] and session RPE) were collected from 13 professional players with 300 session records. Three playing positions were considered: guards (n = 4), forwards (n = 4), and centers (n = 5). High and total external variables (hJUMP and tJUMP, hACC and tACC, hDEC and tDEC, and hCOD and tCOD) were used for the principal-component analysis. Extraction criteria were set at an eigenvalue of greater than 1. Varimax rotation mode was used to extract multiple principal components. Results: The analysis showed that all positions had 2 or 3 principal components (explaining almost all of the variance), but the configuration of each factor was different: tACC, tDEC, tCOD, and hJUMP for centers; hACC, tACC, tCOD, and hJUMP for guards; and tACC, hDEC, tDEC, hCOD, and tCOD for forwards are specifically demanded in training sessions, and therefore these variables must be prioritized in load monitoring. Furthermore, for all playing positions, RPE and session RPE have high correlation with the total amount of ACC, DEC, and COD. This would suggest that although players perform the same training tasks, the demands of each position can vary. Conclusion: A particular combination of external-load measures is required to describe the training load of each playing position, especially to better understand internal responses among players.

Use of an electronic tongue in the assessment of highly diluted systems

2021 ◽  
Vol 10 (36) ◽  
pp. 104-107
Author(s):  
Mateus Silva Laranjeira ◽  
Marilisa Guimarães Lara ◽  
Marco Vinicius Chaud ◽  
Olney Leite Fontes ◽  
Antônio Riul Jr
Keyword(s):  
Ultrathin Films ◽  
Electronic Tongue ◽  
Principal Component ◽  
Original Data ◽  
Relevant Information ◽  
Statistical Correlation ◽  
Layer By Layer ◽  
Layer Technique ◽  
Liquid Systems ◽  
Complex Liquid

Introduction: “Eletronic tongue” is a device commonly used in the analysis of tastants, heavy metal ions, fruit juice, wines and also in the development of biosensors [1-3]. Briefly, the e-tongue is constituted by sensing units formed by ultrathin films of distinct materials deposited on gold interdigitated electrodes, which are immersed in liquid samples, followed by impedance spectroscopy measurements [1]. The e-tongue sensor is based on the global selectivity concept, i.e., the materials forming the sensing units are not selective to any substance in the samples, therefore, it allows the grouping of information into distinct patterns of response, enabling the distinction of complex liquid systems [1]. Aim: Our aim was to use e-tongue system for the assessment the homeopathic medicine Belladonna at different degrees of dilution, in attempt to differentiate highly diluted systems. Methods: Ultrathin films forming the sensing units were prepared by the layer-by-layer technique [4], using conventional polyelectrolytes such as poly(sodium styene sulfonate) (PSS) and poly(allylamine) hydrochloride (PAH), chitosan and poly(3,4-ethylenedioxythiophene) (PEDOT). Homeopathic medicines (Belladonna 1cH, 6cH, 12cH and 30cH) were prepared by dilution and agitation according to Hahnemann´s method [5], using ethanol at 30% (w/w) as vehicle. Experimental data acquisition was conducted by blind tests measurements involving Belladonna samples and the vehicle used in the dilutions. Five independent and consecutive measurements were taken for each solution at 1 kHz, which were further analysed by Principal Component Analysis (PCA), a statistical method largely employed to reduce the dimensionality of the original data without losing information in the correlation of the samples [3]. Results: Figure 1 shows that the five independent measurements are grouped quite closed each other for each solution analysed, with a clear distinction of them. Therefore, it was noticed a change in the observed pattern measured at different days, indicating a reduced reproducibility, although the groups of data could still be identified. Discussion: PCA is a powerful tool highly employed to extract relevant information in the correlation of data analysis of e-tongue systems. PCA plots showed a good statistical correlation of the systems (PC1 + PC2 ³ 90%), with the solutions being straightforwardly distinguished each other and also from the vehicle used. Conclusion: Despite the differences of data obtained along distinct days of analysis, the e-tongue could detect differences among the samples tested, even considering the highly diluted cases studied.

Integrated solid-state wearable sweat sensor system for sodium and potassium ion concentration detection

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Haowei Zhang ◽  
Lili Sun ◽  
Chengli Song ◽  
Ying Liu ◽  
Xueting Xuan ◽  
...  
Keyword(s):  
Solid State ◽  
Real Time ◽  
Ion Concentration ◽  
Sensor System ◽  
Linear Potential ◽  
Sensor Systems ◽  
Electrode Arrays ◽  
Content Type ◽  
Sensing Applications ◽  
High Degree

Purpose Design, fabricate and evaluate all-solid-state wearable sensor systems that can monitor ion concentrations in human sweat to provide real time health analysis and disease diagnosis capabilities. Design/methodology/approach A human health monitoring system includes disposable customized flexible electrode array and a compact signal transmission-processing electronic unit. Findings Patterned rGO (reduced-graphene oxide) layers can replace traditional metal electrodes for the fabrication of free-standing all solid film sensors to provide improved flexibility, sensitivity, selectivity, and stability in ion concentration monitoring. Electrochemical measurements show the open circuit potential of current selective electrodes exhibit near Nernst responses versus Na+ and K+ ion concentration in sweat. These signals show great stability during a typical measurement period of 3 weeks. Sensor performances evaluated through real time measurements on human subjects show strong correlations between subject activity and sweating levels, confirming high degree of robustness, sensitivity, reliability and practicality of current sensor systems. Originality/value In improving flexibility, stability and interfacial coherency of chemical sensor arrays, rGO films have been the developed as a high-performance alternative to conventional electrode with significant cost and processing complexity reduction. rGO supported solid state electrode arrays have been found to have linear potential response versus ion concentration, suitable for electrochemical sensing applications. Current sweat sensor system has a high degree of integration, including electrode arrays, signal processing circuits, and data visualization interfaces.

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