Detection of Anthracene in Real Water Samples with a Label-Free Amperometric Immunosenor

2011 ◽  
Vol 183-185 ◽  
pp. 547-551 ◽  
Author(s):  
Yan Zhang ◽  
Ping Ge Dian ◽  
Hui Sheng Zhuang
Keyword(s):  
Detection Limit ◽  
Prussian Blue ◽  
Water Samples ◽  
Gold Film ◽  
Polyclonal Antibodies ◽  
Current Response ◽  
Label Free ◽  
Long Term Stability

A label-free amperometric immunosenor for determination of anthracene was developed. Prussian blue was electrodeposited on the glassy carbon electrode and then modified with nanometer-size gold film to protect Prussian blue layer and immobilized anthracene polyclonal antibodies. The characteristics of the modified electrode at different stages of modification were studied by cyclic voltammetry. The performances of the amperometric immunosensor were studied in detail. At the optimal experimental condition, the current response of the immunosensor was proportional to the concentration of anthracene in the range of 1.8~90 ng•mL-1with a detection limit of 0.82 ng•mL-1(S/N=3). The studied immunosensor exhibited low detection limit, long-term stability and easy regenerated. This mothod was applied to the anthracene detection in river water samples with satisfied results.

Label-Free Aptamer Fluorescence Determination of Trace Pb2+ Using AuPd Nanoalloy Probe as Catalyst

2013 ◽  
Vol 631-632 ◽  
pp. 18-21 ◽  
Author(s):  
Zhi Liang Jiang ◽  
Mei Ling Tang ◽  
Qing Ye Liu ◽  
Ai Hui Liang
Keyword(s):  
Detection Limit ◽  
Fluorescence Quenching ◽  
Fluorescence Intensity ◽  
Water Samples ◽  
Catalytic Effect ◽  
Rhodamine 6G ◽  
Label Free ◽  
Double Stranded Dna ◽  
Fluorescence Determination

In the condition of 1.24 mmol/L EDTANa2, 16.7 mmol/L NaCl and 0.17 mmol/L Tris, the substrate chain of double-stranded DNA (dsDNA) could be cracked by Pb2+ to release single-stranded DNA (ssDNA) that adsorb onto AuPd nanoparticle (AuPdNP) and form stable AuPdNP-ssDNA, but the dsDNA can not protect AuPdNP that were aggregated to big AuPdNP aggregations (AuPdNPA) under the action of NaCl. The AuPdNP-ssDNA and AuPdNPA could be separated by centrifugation. With the concentration of Pb2+ increased, the released ssDNA increased, the AuPdNP-ssDNA in centrifugation solution increased and the catalytic effect enhanced on the fluorescence quenching reaction of Rhodamine 6G (Rh6G) and NaH2PO2, which led the fluorescence intensity at 552nm to decrease. The decreased fluorescence intensity (ΔF552nm) was linear to the concentration of Pb2+ in the range of 0.33-8.00 nmol/L, a detection limit of 0.21 nmol/L. The proposed method was applied to detect Pb2+ in water samples, with satisfactory results.

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.

Determination of Ochratoxin A in Feed by Immunoaffinity Cleanup and Liquid Chromatography

2013 ◽  
Vol 96 (3) ◽  
pp. 599-602 ◽  
Author(s):  
Ping Ding ◽  
Ziyou Mi ◽  
Yali Hou ◽  
Yigang He ◽  
Jianhua Xie
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Ochratoxin A ◽  
Cyanogen Bromide ◽  
Polyclonal Antibodies ◽  
Immunoaffinity Column ◽  
Low Levels ◽  
Sepharose 4B ◽  
Feed Samples

Abstract A method using LC was developed for determination of ochratoxin A (OTA) in feeds. The extracted samples were cleaned up by an immunoaffinity column prepared by covalently coupling polyclonal antibodies against OTA to cyanogen bromide-activated Sepharose 4B. The eluates were determined by LC with fluorescence detection. Recoveries of OTA from fortified samples of 1–10 μg/kg levels ranged from 84.3 to 90.0%, with CVs of 3.3–7.8%. The detection limit was 0.045 μg/kg based on an S/N of 3:1. A total of 65 feed samples were screened for OTA with the proposed method. The results showed that only nine samples were contaminated with OTAs at low levels. The presented method was successfully applied to quantify OTAs in real feed samples.

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.

A Hydride Generation-Nanosilver Surface Plasmon Resonance Absorption Spectral Method for the Determination of Trace Se(IV)

2013 ◽  
Vol 749 ◽  
pp. 491-494
Author(s):  
Ai Hui Liang ◽  
Qing Ye Liu ◽  
Gui Qing Wen ◽  
Ting Sheng Li ◽  
Zhi Liang Jiang
Keyword(s):  
Surface Plasmon Resonance ◽  
Detection Limit ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Water Samples ◽  
Hydride Generation ◽  
Resonance Absorption ◽  
Surface Plasmon Resonance Absorption ◽  
Hcl Solution

In HCl solution, the Se (IV) was reduced to SeH2 by NaBH4, and absorbed by solution of ethanol-AgNO3. The Ag+ was reduced to nanosilver that exhibited surface plasmon resonance absorption (SPR) peaks at 292 nm and 420 nm. Under the selected conditions, the value at 292 nm was linear to the concentration of Se (IV) in the range of 0.08-2.0 μg/mL, a detection limit of 0.04 μg/mL. The proposed method was applied to detect Se (IV) in water samples, with satisfactory results.

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 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.

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.

A Comparative Study on the Analysis Methods for Chlorophyll-a

2013 ◽  
Vol 726-731 ◽  
pp. 1411-1415 ◽  
Author(s):  
Fei Peng ◽  
Shi Bo Liu ◽  
Hai Yan Xu ◽  
Zhi Qun Li
Keyword(s):  
Detection Limit ◽  
Chlorophyll A ◽  
Water Samples ◽  
Chlorophyll A Fluorescence ◽  
Standard Procedure ◽  
Fluorescence Method ◽  
Monitoring Method ◽  
Detection Range ◽  
Analysis Methods

This paper investigated three chlorophyll-a analysis methods in water sample. The UV-VIS spectrophotometry method followed SL88-2012 standard procedure, the results showed the detection limit of chlorophyll-a was 0.22 μg/L, with the lower detection limit of 1.0 μg/L. The detection range of the vivo chlorophyll-a fluorescence method was 0.1-300μg/L, the ratios of different algae matched that prepared in water samples. The detection limits and quantification limits for HPLC by using UVD and FLD were respectively 0.013 and 0.004 μg/L, 0.040 and 0.013μg/L. FLD was more sensitive than UVD for chlorophyll-a analysis, and the recovery of standard addition was in the range of 90.2% to 103.9% with UVD and FLD. Given the different pretreatment procedures of the sample, equipment conditions, correction and precision, vivo chlorophyll-a fluorescence method was the best on-site monitoring and the emergency monitoring method. Spectrophotometer was suitable for routine laboratory determination of chlorophyll-a, especially for bulk water samples. HPLC method had high precision and sensitivity, so this method applied to the determination of exact requirements, microanalysis and pigment separation.

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