Rapid Label-free Protein Detection Arrays on Coated Silicon Wafers

2006 ◽  
Vol 951 ◽  
Author(s):  
Christopher C. Striemer ◽  
Charles R. Mace ◽  
Benjamin L. Miller
Keyword(s):  
Dynamic Range ◽  
Direct Detection ◽  
Protein Detection ◽  
Ccd Camera ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Solution Concentration ◽  
Label Free ◽  
Probe Molecules ◽  
Target Binding

ABSTRACTWe are developing label-free Arrayed Imaging Reflectometry (AIR) for rapid and multiplexed protein detection. AIR is based on the high dynamic range in reflected optical intensity near a point of zero reflectance on an antireflection coated substrate. The reflectance is therefore highly sensitive to changes in film thickness, allowing direct detection of molecular binding when appropriate probe molecules are immobilized on the surface. The simplest implementation of AIR uses a 633 nm HeNe laser and a silicon wafer substrate coated with ∼1400 Å of SiO2. This system has a reflectance zero for s-polarized HeNe light incident at ∼70°. This interference film is then functionalized with probe molecules designed to bind to a specific target, and this binding can be detected with high sensitivity in the reflectance signal. By expanding the laser beam and collecting the reflected signal with a CCD camera, large arrays of detection spots can be imaged simultaneously. Spot intensity increases relative to the amount of target binding and the target solution concentration can then be calculated. We have demonstrated the detection of the Enteropathogenic E Coli membrane protein Intimin at levels below 10 pM using receptor molecule Tir as a probe, and are currently evaluating various clinical targets using more common antibody probes.

scholarly journals High-frequency rectifiers based on type-II Dirac fermions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Libo Zhang ◽  
Zhiqingzi Chen ◽  
Kaixuan Zhang ◽  
Lin Wang ◽  
Huang Xu ◽  
...  
Keyword(s):  
High Frequency ◽  
Dynamic Range ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Anisotropy Ratio ◽  
Dirac Fermions ◽  
Topological States ◽  
Topological Semimetals ◽  
Polarized Surface ◽  
Symmetry Protected

AbstractThe advent of topological semimetals enables the exploitation of symmetry-protected topological phenomena and quantized transport. Here, we present homogeneous rectifiers, converting high-frequency electromagnetic energy into direct current, based on low-energy Dirac fermions of topological semimetal-NiTe2, with state-of-the-art efficiency already in the first implementation. Explicitly, these devices display room-temperature photosensitivity as high as 251 mA W−1 at 0.3 THz in an unbiased mode, with a photocurrent anisotropy ratio of 22, originating from the interplay between the spin-polarized surface and bulk states. Device performances in terms of broadband operation, high dynamic range, as well as their high sensitivity, validate the immense potential and unique advantages associated to the control of nonequilibrium gapless topological states via built-in electric field, electromagnetic polarization and symmetry breaking in topological semimetals. These findings pave the way for the exploitation of topological phase of matter for high-frequency operations in polarization-sensitive sensing, communications and imaging.

scholarly journals 2D Legendre Moments-Based Visual Control

2012 ◽  
Vol 162 ◽  
pp. 487-496 ◽  
Author(s):  
Aurelien Yeremou Tamtsia ◽  
Youcef Mezouar ◽  
Philippe Martinet ◽  
Haman Djalo ◽  
Emmanuel Tonye
Keyword(s):  
Visual Servoing ◽  
Dynamic Range ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Interaction Matrix ◽  
Geometric Moments ◽  
Control Scheme ◽  
Control Schemes ◽  
Legendre Moments ◽  
Set Of Points

Among region-based descriptors, geometric moments have been widely exploited to design visual servoing schemes. However, they present several disadvantages such as high sensitivity to noise measurement, high dynamic range and information redundancy (since they are not computed onto orthogonal basis). In this paper, we propose to use a class of orthogonal moments (namely Legendre moments) instead of geometric moments to improve the behavior of moment-based control schemes. The descriptive form of the interaction matrix related to the Legendre moments computed from a set of points is rst derived. Six visual features are then selected to design a partially-decoupled control scheme. Finally simulated and experimental results are presented to illustrate the validity of our proposal.

scholarly journals Methods for Voltage-Sensitive Dye Imaging of Rat Cortical Activity With High Signal-to-Noise Ratio

2007 ◽  
Vol 98 (1) ◽  
pp. 502-512 ◽  
Author(s):  
Michael T. Lippert ◽  
Kentaroh Takagaki ◽  
Weifeng Xu ◽  
Xiaoying Huang ◽  
Jian-Young Wu
Keyword(s):  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Field Potential ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
High Signal ◽  
Blue Dye ◽  
Voltage Sensitive Dye ◽  
Imaging Device

We describe methods to achieve high sensitivity in voltage-sensitive dye (VSD) imaging from rat barrel and visual cortices in vivo with the use of a blue dye RH1691 and a high dynamic range imaging device (photodiode array). With an improved staining protocol and an off-line procedure to remove pulsation artifact, the sensitivity of VSD recording is comparable with that of local field potential recording from the same location. With this sensitivity, one can record from ∼500 individual detectors, each covering an area of cortical tissue 160 μm in diameter (total imaging field ∼4 mm in diameter) and a temporal resolution of 1,600 frames/s, without multiple-trial averaging. We can record 80–100 trials of intermittent 10-s trials from each imaging field before the VSD signal reduces to one half of its initial amplitude because of bleaching and wash-out. Taken together, the methods described in this report provide a useful tool for visualizing evoked and spontaneous waves from rodent cortex.

scholarly journals Electronic Optical Sky Surveys

1998 ◽  
Vol 179 ◽  
pp. 49-55
Author(s):  
T.A. McKay
Keyword(s):  
Dynamic Range ◽  
Large Fraction ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Low Noise ◽  
Computer Hardware ◽  
Optical Detectors ◽  
Small Fields ◽  
Technical Advances ◽  
High Dynamic

The introduction of of Charge Coupled Devices (CCDs) in the middle 1970s provided astronomy with nearly perfect (linear, high-sensitivity, low-noise, high dynamic-range, digital) optical detectors. Unfortunately, restrictions imposed by CCD production and cost has typically limited their use to observations of relatively small fields. Recently a combination of technical advances have made practical the application of CCDs to survey science. CCD mosaic cameras, which help overcome the size restrictions imposed by CCD manufacture, allow electronic access to a larger fraction of the available focal plane. Multi-fiber spectrographs, which couple the low-noise, high QE performance of CCDs with the ability to observe spectra for many objects at once, have improved the spectroscopic efficiency of telescopes by factors approaching half a million. An improved understanding of image distortion gives us telescopes on which we expect sub-arcsecond images a large fraction of the time. Finally, and perhaps most important, the performance of computer hardware continues to advance, to the point where analysis of multi-terabyte datasets, while still daunting, is at least conceivable.

A theoretical study of digital silicon photomultiplier utilization in diffuse optical imaging systems

2019 ◽  
Vol 64 (3) ◽  
pp. 357-363 ◽  
Author(s):  
Taha Haddadifam ◽  
Mohammad Azim Karami
Keyword(s):  
Optical Imaging ◽  
Continuous Wave ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Diffuse Optical Imaging ◽  
Silicon Photomultiplier ◽  
Thoracic Imaging ◽  
Low Level

Abstract Digital silicon photomultiplier (dSiPM) is introduced for diffuse optical imaging (DOI) applications instead of conventional photomultiplier tubes and avalanche photodiodes (APDs) as a state-of-the-art detector. According to the low-level light regime in DOI applications, high sensitivity and high dynamic range (DR) image sensors are needed for DOI systems. dSiPM is proposed as a developing detector which can detect low-level lights. Also, an accurate equation is obtained for calculating the DR of dSiPMs. Different dSiPMs and the corresponding benefits are studied for DOI applications. Furthermore, a 120 dB DR dSiPM is chosen for use in DOI systems. It is shown that dSiPMs can be utilized in DOI configurations such as time domain (TD), frequency domain (FD) and continuous wave (CW) systems. Ultimately, by utilizing dSiPM in DOI systems, the DOI method can be used for thoracic imaging due to the high DR and signal-to-noise ratio (SNR) of the detector.

scholarly journals Performance assessment of imaging plates for the JHR transfer Neutron Imaging System

2018 ◽  
Vol 170 ◽  
pp. 04021
Author(s):  
E. Simon ◽  
P. Guimbal
Keyword(s):  
Performance Assessment ◽  
Dynamic Range ◽  
Imaging System ◽  
Computed Radiography ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Neutron Imaging ◽  
Imaging Plate ◽  
Intimate Contact ◽  
Imaging Plates

The underwater Neutron Imaging System to be installed in the Jules Horowitz Reactor (JHR-NIS) is based on a transfer method using a neutron activated beta-emitter like Dysprosium. The information stored in the converter is to be offline transferred on a specific imaging system, still to be defined. Solutions are currently under investigation for the JHR-NIS in order to anticipate the disappearance of radiographic films commonly used in these applications. We report here the performance assessment of Computed Radiography imagers (Imaging Plates) performed at LLB/Orphée (CEA Saclay). Several imaging plate types are studied, in one hand in the configuration involving an intimate contact with an activated dysprosium foil converter: Fuji BAS-TR, Fuji UR-1 and Carestream Flex XL Blue imaging plates, and in the other hand by using a prototypal imaging plate doped with dysprosium and thus not needing any contact with a separate converter foil. The results for these imaging plates are compared with those obtained with gadolinium doped imaging plate used in direct neutron imaging (Fuji BAS-ND). The detection performances of the different imagers are compared regarding resolution and noise. The many advantages of using imaging plates over radiographic films (high sensitivity, linear response, high dynamic range) could palliate its lower intrinsic resolution.

scholarly journals Analysis of space-resolved X-ray spectra from laser plasmas

2002 ◽  
Vol 20 (2) ◽  
pp. 223-226 ◽  
Author(s):  
L. LABATE ◽  
M. GALIMBERTI ◽  
A. GIULIETTI ◽  
D. GIULIETTI ◽  
L.A. GIZZI ◽  
...  
Keyword(s):  
Electron Density ◽  
Ad Hoc ◽  
Dynamic Range ◽  
Spherical Geometry ◽  
Ccd Camera ◽  
High Dynamic Range ◽  
Electron Density Profile ◽  
Temperature Profiles ◽  
X Ray ◽  
Numerical Predictions

High dynamic range, space-resolved X-ray spectra, obtained using a TlAP crystal and a cooled CCD camera as a detector, were used to investigate the electron density and temperature profiles of an aluminum laser plasma with micrometer resolution. The electron density profile retrieved from the measurements is compared with numerical predictions from the two hydrodynamics codes MEDUSA (1D) and POLLUX (2D). It is shown that 2D density profiles can be successfully reproduced by 1D simulations using a spherical geometry with an ad hoc initial radius, leading to similar electron temperature profiles.

scholarly journals High-Speed Interferometric Detection of Label-Free Immunoassays on the Biological Compact Disc

2006 ◽  
Vol 52 (11) ◽  
pp. 2135-2140 ◽  
Author(s):  
Ming Zhao ◽  
David Nolte ◽  
Wonryeon Cho ◽  
Fred Regnier ◽  
Manoj Varma ◽  
...  
Keyword(s):  
High Speed ◽  
Direct Detection ◽  
High Sensitivity ◽  
Compact Disc ◽  
Periodic Pattern ◽  
Label Free ◽  
Protein Patterns ◽  
Igg Antibody ◽  
Local Reference ◽  
Interferometric Detection

Abstract Background: We describe a direct-detection immunoassay that uses high-speed optical interferometry on a biological compact disc (BioCD). Methods: We fabricated phase-contrast BioCDs from 100-mm diameter 1.1-mm thick borosilicate glass disks coated with a 10-layer dielectric stack of Ta2O5/SiO2 that serves as a mirror with a center wavelength at 635 nm. The final layer is a λ/4 layer of SiO2 onto which protein patterns are immobilized through several different chemical approaches. Protein on the disc is scanned by a focused laser spot as the disc spins. Interaction of the light with the protein provides both a phase-modulated signal and a local reference that are combined interferometrically to convert phase into intensity. A periodic pattern of protein on the spinning disc produces an intensity modulation as a function of time that is proportional to the surface-bound mass. The binding of antigen or antibodies is detected directly, without labels, by a change in the interferometric intensity. The technique is demonstrated with a reverse assay of immobilized rabbit and mouse IgG antigen incubated against anti-IgG antibody in a casein buffer. Results: The signal increased with increased concentration of analyte. The current embodiment detected a concentration of 100 ng/L when averaged over ∼3000 100-micron-diameter protein spots. Conclusions: High-speed interferometric detection of label-free protein assays on a rapidly spinning BioCD is a high-sensitivity approach that is amenable to scaling up to many analytes.

Electrical Detection of Protein Biomarkers Using Nanoneedle Biosensors

2012 ◽  
Vol 1414 ◽  
Author(s):  
Rahim Esfandyarpour ◽  
Hesaam Esfandyarpour ◽  
Mehdi Javanmard ◽  
James S. Harris ◽  
Ronald W. Davis
Keyword(s):  
Physical Adsorption ◽  
Ionic Current ◽  
Microfluidic Channel ◽  
Protein Detection ◽  
High Sensitivity ◽  
Receptor Protein ◽  
Label Free ◽  
Electrical Detection ◽  
Protein Biomarkers ◽  
Impedance Modulation

Abstract:Here we present the development of an array of electrical nano-biosensors in a microfluidic channel, called Nanoneedle biosensors. Then we present the proof of concept study for protein detection. A Nanoneedle biosensor is a real-time, label-free, direct electrical detection platform, which is capable of high sensitivity detection, measuring the change in ionic current and impedance modulation, due to the presence or reaction of biomolecules such as proteins or nucleic acids. We show that the sensors which have been fabricated and characterized for the protein detection. We have functionalized Nanoneedle biosensors with receptors specific to a target protein using physical adsorption for immobilization. We have used biotinylated bovine serum albumin as the receptor and sterptavidin as the target analyte. The detection of streptavidin binding to the receptor protein is also presented.

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