Label-Free Biosensing Using Diffractive Optical Analysis

Label-free, mass-sensitive single-molecule imaging using interferometric scattering microscopy

Essays in Biochemistry ◽

10.1042/ebc20200023 ◽

2020 ◽

Author(s):

Nikolas Hundt

Keyword(s):

Single Molecule ◽

Cellular Systems ◽

Single Molecule Imaging ◽

Label Free ◽

Measurement Sensitivity ◽

Mass Distributions ◽

Quantitative Measurements ◽

Contrast Mechanism ◽

Cellular Components ◽

Scattering Signal

Abstract Single-molecule imaging has mostly been restricted to the use of fluorescence labelling as a contrast mechanism due to its superior ability to visualise molecules of interest on top of an overwhelming background of other molecules. Recently, interferometric scattering (iSCAT) microscopy has demonstrated the detection and imaging of single biomolecules based on light scattering without the need for fluorescent labels. Significant improvements in measurement sensitivity combined with a dependence of scattering signal on object size have led to the development of mass photometry, a technique that measures the mass of individual molecules and thereby determines mass distributions of biomolecule samples in solution. The experimental simplicity of mass photometry makes it a powerful tool to analyse biomolecular equilibria quantitatively with low sample consumption within minutes. When used for label-free imaging of reconstituted or cellular systems, the strict size-dependence of the iSCAT signal enables quantitative measurements of processes at size scales reaching from single-molecule observations during complex assembly up to mesoscopic dynamics of cellular components and extracellular protrusions. In this review, I would like to introduce the principles of this emerging imaging technology and discuss examples that show how mass-sensitive iSCAT can be used as a strong complement to other routine techniques in biochemistry.

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Optical analysis of ink and other contaminants in process waters

TAPPI Journal ◽

10.32964/tj11.8.51 ◽

2012 ◽

Vol 11 (8) ◽

pp. 51-58

Author(s):

ANTTI HAAPALA ◽

MIKA KÖRKKÖ ◽

ELISA KOIVURANTA ◽

JOUKO NIINIMÄKI

Keyword(s):

Optically Active ◽

Process Water ◽

Paper Machine ◽

Optical Analysis ◽

Direct Process ◽

Active Components ◽

Water Contaminants ◽

Dependent Measurement ◽

Measurement Methodology

Analysis methods developed specifically to determine the presence of ink and other optically active components in paper machine white waters or other process effluents are not available. It is generally more interest¬ing to quantify the effect of circulation water contaminants on end products. This study compares optical techniques to quantify the dirt in process water by two methods for test media preparation and measurement: direct process water filtration on a membrane foil and low-grammage sheet formation. The results show that ink content values obtained from various analyses cannot be directly compared because of fundamental issues involving test media preparation and the varied methodologies used to formulate the results, which may be based on different sets of assumptions. The use of brightness, luminosity, and reflectance and the role of scattering measurements as a part of ink content analysis are discussed, along with fine materials retention and measurement media selection. The study concludes with practical tips for case-dependent measurement methodology selection.

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A microfluidic device with integrated impedance detection for λ-DNA

MRS Proceedings ◽

10.1557/proc-773-n6.5 ◽

2003 ◽

Vol 773 ◽

Cited By ~ 1

Author(s):

Myung-Il Park ◽

Jonging Hong ◽

Dae Sung Yoon ◽

Chong-Ook Park ◽

Geunbae Im

Keyword(s):

Microfluidic Device ◽

Electrochemical Impedance ◽

Direct Detection ◽

Full Potential ◽

Label Free ◽

Buffer Solution ◽

Detection Systems ◽

Significant Difference ◽

Detection Of Biomolecules ◽

Impedance Magnitude

AbstractThe large optical detection systems that are typically utilized at present may not be able to reach their full potential as portable analysis tools. Accurate, early, and fast diagnosis for many diseases requires the direct detection of biomolecules such as DNA, proteins, and cells. In this research, a glass microchip with integrated microelectrodes has been fabricated, and the performance of electrochemical impedance detection was investigated for the biomolecules. We have used label-free λ-DNA as a sample biomolecule. By changing the distance between microelectrodes, the significant difference between DW and the TE buffer solution is obtained from the impedance-frequency measurements. In addition, the comparison for the impedance magnitude of DW, the TE buffer, and λ-DNA at the same distance was analyzed.

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In Vivo Optical Analysis of Quantitative Changes in Collagen and Elastin During Arterial Remodeling¶

Photochemistry and Photobiology ◽

10.1562/2004-03-10-ra-107.1 ◽

2005 ◽

Vol 81 (2) ◽

pp. 457 ◽

Cited By ~ 19

Author(s):

Alexander Christov ◽

Renee M. Korol ◽

Erbin Dai ◽

Liying Liu ◽

Haiyan Guan ◽

...

Keyword(s):

Arterial Remodeling ◽

Optical Analysis ◽

Quantitative Changes

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Aero-optical analysis of compressible flow over an open cavity

10.2514/6.1987-1399 ◽

1987 ◽

Author(s):

PHILIP CASSADY ◽

STANLEY BIRCH ◽

P. TERRY

Keyword(s):

Compressible Flow ◽

Open Cavity ◽

Optical Analysis

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VLSI for Space Applications—Single Event Effect Investigation and Optical Analysis on an Integrated Laser Platform

ISTFA 2017: Conference Proceedings from the 43rd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2017p0621 ◽

2017 ◽

Author(s):

Samuel Chef ◽

Chung Tah Chua ◽

Yu Wen Siah ◽

Philippe Perdu ◽

Chee Lip Gan ◽

...

Keyword(s):

Pulsed Laser ◽

Single Event ◽

Optical Analysis ◽

Space Applications ◽

Laser Probing ◽

Single Event Effect ◽

Evaluation Time ◽

Black Boxes ◽

System Use ◽

First Time

Abstract Today’s VLSI devices are neither designed nor manufactured for space applications in which single event effects (SEE) issues are common. In addition, very little information about the internal schematic and usually nothing about the layout or netlist is available. Thus, they are practically black boxes for satellite manufacturers. On the other hand, such devices are crucial in driving the performance of spacecraft, especially smaller satellites. The only way to efficiently manage SEE in VLSI devices is to localize sensitive areas of the die, analyze the regions of interest, study potential mitigation techniques, and evaluate their efficiency. For the first time, all these activities can be performed using the same tool with a single test setup that enables a very efficient iterative process that reduce the evaluation time from months to days. In this paper, we will present the integration of a pulsed laser for SEE study into a laser probing, laser stimulation, and emission microscope system. Use of this system will be demonstrated on a commercial 8 bit microcontroller.

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