scholarly journals High-Sensitivity Detection of IgG Operating near the Dispersion Turning Point in Tapered Two-Mode Fibers

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 270
Author(s):  
Bing Sun ◽  
Yiping Wang
Keyword(s):  
Turning Point ◽  
High Sensitivity ◽  
Wavelength Shift ◽  
Label Free ◽  
Trace Detection ◽  
Detection Scheme ◽  
Simple Detection ◽  
Assay Time ◽  
Resonant Wavelength Shift ◽  
High Sensitivity Detection

The conventional methods for monitoring IgG levels suffer from some apparent problems such as long assay time, multistep processing, and high overall cost. An effective and suitable optical platform for label-free biosensing was investigated by the implementation of antibody/antigen immunoassays. The ultrasensitive detection of IgG levels could be achieved by exploiting the dispersion turning point (DTP) existing in the tapered two-mode fibers (TTMFs) because the sensitivity will reach ±∞ on either side of the DTP. Tracking the resonant wavelength shift, it was found that the fabricated TTMF device exhibited limits of detection (LOD) down to concentrations of 10 fg/mL of IgG in PBS solution. Such immunosensors based on DTP have great significance on trace detection of IgG due to simple detection scheme, quick response time, and miniaturization.

High sensitivity detection scheme for corona discharge radiation signal

2014 ◽  
Vol 26 (3) ◽  
pp. 33201
Author(s):  
朱利 Zhu Li ◽  
刘尚合 Liu Shanghe ◽  
张悦 Zhang Yue ◽  
樊高辉 Fan Gaohui
Keyword(s):  
Corona Discharge ◽  
High Sensitivity ◽  
Detection Scheme ◽  
High Sensitivity Detection ◽  
Sensitivity Detection

scholarly journals Graphene based electrochemical immunosensor for the ultra-sensitive label free detection of Alzheimer’s beta amyloid peptides Aβ(1-42)

2021 ◽  
Author(s):  
Hina Yaqub Abbasi ◽  
Zari Tehrani ◽  
Anitha Devadoss ◽  
Muhammad Ali ◽  
Soraya Moradi-Bachiller ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
High Sensitivity ◽  
Beta Amyloid ◽  
Electrochemical Immunosensor ◽  
Label Free ◽  
Amyloid Peptides ◽  
Label Free Detection ◽  
High Sensitivity Detection ◽  
Sensitivity Detection ◽  
Screen Printed

An immunosensor, capable of high sensitivity detection of beta-amyloid peptides, shown to be a reliable biomarker for Alzheimer’s disease, has been developed using screen printed graphene electrodes (SPGEs) modified with...

High-sensitivity detection of gold labels by high-angle dark-field STEM imaging

1990 ◽  
Vol 48 (3) ◽  
pp. 892-893 ◽  
Author(s):  
Max T. Otten
Keyword(s):  
High Sensitivity ◽  
Dark Field ◽  
Bright Field ◽  
Backscattered Electron Imaging ◽  
Backscattered Electrons ◽  
Average Atomic Number ◽  
Highly Sensitive ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
High Sensitivity Detection

Labelling of antibodies with small gold probes is a highly sensitive technique for detecting specific molecules in biological tissue. Larger gold probes are usually well visible in TEM or STEM Bright-Field images of unstained specimens. In stained specimens, however, the contrast of the stain is frequently the same as that of the gold labels, making it virtually impossible to identify the labels, especially when smaller gold labels are used to increase the sensitivity of the immunolabelling technique. TEM or STEM Dark-Field images fare no better (Figs. 1a and 2a), again because of the absence of a clear contrast difference between gold labels and stain.Potentially much more useful is backscattered-electron imaging, since this will show differences in average atomic number which are sufficiently large between the metallic gold and the stains normally used. However, for the thin specimens and at high accelerating voltages of the STEM, the yield of backscattered electrons is very small, resulting in a very weak signal. Consequently, the backscattered-electron signal is often too noisy for detecting small labels, even for large spot sizes.

Label-free and Simple Detection of Trace Pb(II) in Tap Water Using Non-faradaic Impedimetric Sensors

2021 ◽  
pp. 112833
Author(s):  
Abdulaziz K. Assaifan ◽  
Mahmoud Hezam ◽  
Mahmoud A. Al-Gawati ◽  
Khaled E. Alzahrani ◽  
Abdullah Alswieleh ◽  
...  
Keyword(s):  
Tap Water ◽  
Label Free ◽  
Simple Detection

scholarly journals Integrating high-performing electrochemical transducers in lateral flow assay

2021 ◽  
Author(s):  
Antonia Perju ◽  
Nongnoot Wongkaew
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
High Sensitivity ◽  
Lateral Flow ◽  
Analytical Performance ◽  
Label Free ◽  
High Performing ◽  
Lateral Flow Assays ◽  
Electrochemical Transducers

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.

scholarly journals Recognition of Bimolecular Logic Operation Pattern Based on a Solid-State Nanopore

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 33
Author(s):  
Han Yan ◽  
Zhen Zhang ◽  
Ting Weng ◽  
Libo Zhu ◽  
Pang Zhang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Detection Method ◽  
Logic Gate ◽  
Detection Methods ◽  
Label Free ◽  
Recognition Method ◽  
Operation Pattern ◽  
Simple Detection ◽  
Dna Tetrahedron ◽  
Marker Molecule

Nanopores have a unique advantage for detecting biomolecules in a label-free fashion, such as DNA that can be synthesized into specific structures to perform computations. This method has been considered for the detection of diseased molecules. Here, we propose a novel marker molecule detection method based on DNA logic gate by deciphering a variable DNA tetrahedron structure using a nanopore. We designed two types of probes containing a tetrahedron and a single-strand DNA tail which paired with different parts of the target molecule. In the presence of the target, the two probes formed a double tetrahedron structure. As translocation of the single and the double tetrahedron structures under bias voltage produced different blockage signals, the events could be assigned into four different operations, i.e., (0, 0), (0, 1), (1, 0), (1, 1), according to the predefined structure by logic gate. The pattern signal produced by the AND operation is obviously different from the signal of the other three operations. This pattern recognition method has been differentiated from simple detection methods based on DNA self-assembly and nanopore technologies.

scholarly journals Microfluidics-Based Plasmonic Biosensing System Based on Patterned Plasmonic Nanostructure Arrays

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 826
Author(s):  
Yanting Liu ◽  
Xuming Zhang
Keyword(s):  
Plasmon Resonance ◽  
Point Of Care ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Microfluidic Chips ◽  
Label Free ◽  
Plasmonic Nanostructure ◽  
Point Of Care Diagnostics ◽  
Surface Enhanced Raman ◽  
Nanostructure Arrays

This review aims to summarize the recent advances and progress of plasmonic biosensors based on patterned plasmonic nanostructure arrays that are integrated with microfluidic chips for various biomedical detection applications. The plasmonic biosensors have made rapid progress in miniaturization sensors with greatly enhanced performance through the continuous advances in plasmon resonance techniques such as surface plasmon resonance (SPR) and localized SPR (LSPR)-based refractive index sensing, SPR imaging (SPRi), and surface-enhanced Raman scattering (SERS). Meanwhile, microfluidic integration promotes multiplexing opportunities for the plasmonic biosensors in the simultaneous detection of multiple analytes. Particularly, different types of microfluidic-integrated plasmonic biosensor systems based on versatile patterned plasmonic nanostructured arrays were reviewed comprehensively, including their methods and relevant typical works. The microfluidics-based plasmonic biosensors provide a high-throughput platform for the biochemical molecular analysis with the advantages such as ultra-high sensitivity, label-free, and real time performance; thus, they continue to benefit the existing and emerging applications of biomedical studies, chemical analyses, and point-of-care diagnostics.

scholarly journals High-sensitivity detection of TNT

2006 ◽  
Vol 103 (52) ◽  
pp. 19630-19634 ◽  
Author(s):  
M. B. Pushkarsky ◽  
I. G. Dunayevskiy ◽  
M. Prasanna ◽  
A. G. Tsekoun ◽  
R. Go ◽  
...  
Keyword(s):  
High Sensitivity ◽  
High Sensitivity Detection ◽  
Sensitivity Detection

Label-free capacitive immunosensors for ultra-trace detection based on the increase of immobilized antibodies on silver nanoparticles

2011 ◽  
Vol 699 (2) ◽  
pp. 232-241 ◽  
Author(s):  
Supaporn Dawan ◽  
Proespichaya Kanatharana ◽  
Booncharoen Wongkittisuksa ◽  
Warakorn Limbut ◽  
Apon Numnuam ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Label Free ◽  
Trace Detection ◽  
Immobilized Antibodies ◽  
Ultra Trace
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