scholarly journals Electrodeposition of Pd-Pt Nanocomposites on Porous GaN for Electrochemical Nitrite Sensing

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 606 ◽  
Author(s):  
Rui Xi ◽  
Shao-Hui Zhang ◽  
Long Zhang ◽  
Chao Wang ◽  
Lu-Jia Wang ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Food Industry ◽  
Biological Process ◽  
High Sensitivity ◽  
Good Reproducibility ◽  
Practical Application ◽  
Long Term Stability ◽  
Nitrite Content

In recent years, nitrite pollution has become a subject of great concern for human lives, involving a number of fields, such as environment, food industry and biological process. However, the effective detection of nitrite is an instant demand as well as an unprecedented challenge. Here, a novel nitrite sensor was fabricated by electrochemical deposition of palladium and platinum (Pd-Pt) nanocomposites on porous gallium nitride (PGaN). The obtained Pd-Pt/PGaN sensor provides abundant electrocatalytic sites, endowing it with excellent performances for nitrite detection. The sensor also shows a low detection limit of 0.95 µM, superior linear ampere response and high sensitivity (150 µA/mM for 1 to 300 µM and 73 µA/mM for 300 to 3000 µM) for nitrite. In addition, the Pd-Pt/PGaN sensor was applied and evaluated in the determination of nitrite from the real environmental samples. The experimental results demonstrate that the sensor has good reproducibility and long-term stability. It provides a practical way for rapidly and effectively monitoring nitrite content in the practical application.

THE ROLE OF POLYETHYLENIMINE IN ENHANCING PERFORMANCE OF GLUTAMATE BIOSENSORS

2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia
Keyword(s):  
First Generation ◽  
Good Reproducibility ◽  
Complex Matrices ◽  
Long Term Stability ◽  
In Vitro Characterization ◽  
Glutamate Oxidase

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors

scholarly journals Using MoS2/Fe3O4 as Ion-Electron Transduction Layer to Manufacture All-Solid-State Ion-Selective Electrode for Determination of Serum Potassium

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 155
Author(s):  
Yan Su ◽  
Ting Liu ◽  
Caiqiao Song ◽  
Aiqiao Fan ◽  
Nan Zhu ◽  
...  
Keyword(s):  
High Performance ◽  
Accurate Determination ◽  
Water Layer ◽  
Ion Selective Electrode ◽  
Potential Response ◽  
Selective Electrode ◽  
Response Measurement ◽  
Long Term Stability

As an essential electrolyte for the human body, the potassium ion (K+) plays many physiological roles in living cells, so the rapid and accurate determination of serum K+ is of great significance. In this work, we developed a solid-contact ion-selective electrode (SC-ISE) using MoS2/Fe3O4 composites as the ion-to-electron transducer to determine serum K+. The potential response measurement of MoS2/Fe3O4/K+-ISE shows a Nernst response by a slope of 55.2 ± 0.1 mV/decade and a low detection limit of 6.3 × 10−6 M. The proposed electrode exhibits outstanding resistance to the interference of O2, CO2, light, and water layer formation. Remarkably, it also presents a high performance in potential reproducibility and long-term stability.

High-performance humidity sensors from Ni(SO4)0.3(OH)1.4 nanobelts

Nanoscale ◽  
2014 ◽  
Vol 6 (12) ◽  
pp. 6521-6525 ◽  
Author(s):  
Ming Zhuo ◽  
Yuejiao Chen ◽  
Tao Fu ◽  
Haonan Zhang ◽  
Zhi Xu ◽  
...  
Keyword(s):  
High Performance ◽  
Humidity Sensor ◽  
High Sensitivity ◽  
Fast Response ◽  
Humidity Sensors ◽  
Term Stability ◽  
Long Term Stability

Ni(SO4)0.3(OH)1.4 nanobelts are utilized in a humidity sensor by a facile method. The nanobelt based sensor shows a high sensitivity, fast response and long-term stability in the sensing process.

Determination of Long-Term Stability and Quality of HT-PEM MEAs

2018 ◽  
Vol 86 (13) ◽  
pp. 301-314
Author(s):  
Maren Rastedt ◽  
Julian Büsselmann ◽  
Tomas Klicpera ◽  
Karsten Reinwald ◽  
Nadine Pilinski ◽  
...  
Keyword(s):  
Term Stability ◽  
Long Term Stability

scholarly journals Separation of Arsenic and Selenium Species by Capillary Zone Electrophoresis in a Coated Capillary

1999 ◽  
Vol 82 (6) ◽  
pp. 1587-1593 ◽  
Author(s):  
Natalia G Vanifatova ◽  
Boris Y Spivakov ◽  
Juergen Mattusch ◽  
Rainer Wennrich
Keyword(s):  
Capillary Zone Electrophoresis ◽  
Sensitivity Enhancement ◽  
Selenium Species ◽  
Long Term Stability ◽  
Zone Electrophoresis ◽  
Electrophoresis Method ◽  
Capillary Zone ◽  
Matrix Removal

Abstract A capillary zone electrophoresis method was developed for the determination of 8 arsenic and selenium species in a polymer-coated capillary. Large-volume stacking with matrix removal was used for sensitivity enhancement. The entire analysis time was only a few minutes. The experimental sensitivity enhancement for 7 species was found to be near its theoretical value. Coating capillaries for long-term stability in alkaline buffer electrolytes was also investigated.

Synthesis of Trilaminar Core–Shell Au/α-Fe2O3@SnO2Nanocomposites and their Application for Nonenzymatic Dopamine Electrochemical Sensing

NANO ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. 1950138 ◽  
Author(s):  
Sai Zhang ◽  
Shijun Yue ◽  
Jiajia Li ◽  
Jianbin Zheng ◽  
Guojie Gao
Keyword(s):  
Electron Microscopy ◽  
High Sensitivity ◽  
Electrochemical Sensing ◽  
Synthesis Process ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Long Term Stability ◽  
Transmission Electron

Au nanoparticles anchored on core–shell [Formula: see text]-Fe2O3@SnO2 nanospindles were successfully constructed through hydrothermal synthesis process and used for fabricating a novel nonenzymatic dopamine (DA) sensor. The structure and morphology of the Au/[Formula: see text]-Fe2O3@SnO2 trilaminar nanohybrid film were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical properties of the sensor were investigated by cyclic voltammetry and amperometry. The experimental results suggest that the composites have excellent catalytic property toward DA with a wide linear range from 0.5[Formula: see text][Formula: see text]M to 0.47[Formula: see text]mM, a low detection limit of 0.17[Formula: see text][Formula: see text]M (S/[Formula: see text]) and high sensitivity of 397.1[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text]. In addition, the sensor exhibits long-term stability, good reproducibility and anti-interference.

scholarly journals Determination of St. George Basilica Tower Historical Inclination from Contemporary Photograph

2011 ◽  
Vol 6 ◽  
pp. 212-219
Author(s):  
Bronislav Koska
Keyword(s):  
Standard Deviation ◽  
Visual Information ◽  
Bundle Adjustment ◽  
Long Term Stability ◽  
The North ◽  
Research Activities ◽  
Geometrical Information ◽  
Historical Photographs

A large amount of photographic material has been accumulated from the photography emerge in the nineteenth century. The most photographs record portraits, urbanistic complex, significant architecture and others important objects in the photography inception. Historical photographs recorded a huge amount of information, which can be use for various research activities. Photograph visual information is sufficient in many cases, but accurate geometrical information must be acquired from it in specific situations. It is the case of long-term stability monitoring of buildings in the Prague Castle area see [1]. For static analysis in the monitoring project, it is necessary to determine accurately specific geometrical parameter – mutual angle of St. George Basilica towers in the north-south direction before the reconstruction started in 1888. The angle standard deviation must be solved as well. The task demanded using of photogrammetric methods. Own implementation of general bundle adjustment had to be created to fulfill determination of reliable standard deviation of the angle, because standard photogrammetric software does not have all the necessary options.

scholarly journals NO2 and NH3 Sensing Characteristics of Inkjet Printing Graphene Gas Sensors

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3379 ◽  
Author(s):  
Caterina Travan ◽  
Alexander Bergmann
Keyword(s):  
Gas Sensors ◽  
Inkjet Printing ◽  
High Mobility ◽  
High Sensitivity ◽  
Low Noise ◽  
Manufacturing Method ◽  
Long Term Stability ◽  
Wide Range ◽  
Ideal Technique

Graphene is a good candidate for filling the market requirements for cheap, high sensitivity, robust towards contamination, low noise, and low power consumption gas sensors, thanks to its unique properties, i.e., large surface, high mobility, and long-term stability. Inkjet printing is a cheap additive manufacturing method allowing fast, relatively precise and contactless deposition of a wide range of materials; it can be considered therefore the ideal technique for fast deposition of graphene films on thin substrates. In this paper, the sensitivity of graphene-based chemiresistor gas sensors, fabricated through inkjet printing, is investigated using different concentrations of graphene in the inks. Samples have been produced and characterized in terms of response towards humidity, nitrogen dioxide, and ammonia. The presented results highlight the importance of tuning the layer thickness and achieving good film homogeneity in order to maximize the sensitivity of the sensor.

scholarly journals Timepix3 Luminosity Determination of 13 TeV Proton-Proton Collisions at the ATLAS Experiment

2020 ◽  
Vol 225 ◽  
pp. 01002
Author(s):  
Andreé Sopczak
Keyword(s):  
Simple Model ◽  
Number Of Clusters ◽  
Proton Proton ◽  
Proton Collisions ◽  
Atlas Experiment ◽  
Long Term Stability ◽  
Counting Methods ◽  
Proton Proton Collisions

Medipix and Timepix devices, installed in the ATLAS cavern at the LHC, have provided valuable complementary luminosity information. Results are presented from measurements with Timepix3 (TPX3) detectors. In contrast with previously employed frame-based data acquisition, the TPX3 detector remains active continuously, sending information on pixel hits as they occur. Hit- and cluster-counting methods were used for the luminosity determination of the LHC protonproton collisions. The LHC luminosity versus time is determined using these two methods and fitted to a simple model, which incorporates luminosity reduction from single bunch and beam-beam interactions. The precision of the luminosity determination could be improved by counting the number of clusters, instead of just pixel hits. The internal precision and long-term stability of the TPX3 luminosity measurement are below 0.5%. TPX3, owing to its 1.56 ns time-tagging, is able to resolve the time structure of the luminosity due to the collisions of individual proton bunches when integrated over an LHC fill.

Long-Term Stability of High Sensitivity C Reactive Protein Levels in Healthy Adults

2007 ◽  
Vol 16 ◽  
pp. S68
Author(s):  
B.M. McQuillan ◽  
E. Rossi ◽  
J. Hung ◽  
P.L. Thompson ◽  
J.P. Beilby
Keyword(s):  
High Sensitivity ◽  
Healthy Adults ◽  
C Reactive Protein ◽  
Term Stability ◽  
Protein Levels ◽  
Long Term Stability ◽  
Reactive Protein
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