A highly sensitive balanced receiver for 2.5 Gb/s heterodyne detection systems

1991 ◽  
Vol 3 (4) ◽  
pp. 375-377 ◽  
Author(s):  
N. Ohkawa ◽  
T. Sugie ◽  
Y. Hayashi
Keyword(s):  
Heterodyne Detection ◽  
Detection Systems ◽  
Highly Sensitive

scholarly journals Highly sensitive biomarker biosensor for early detection of cancer biomarkers

2021 ◽  
Author(s):  
Jaydev Upponi ◽  
Tiziana Musacchio ◽  
Salome Siavoshi ◽  
Asanterabi Malima ◽  
Cihan Yilmaz ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Early Detection ◽  
Carcinoembryonic Antigen ◽  
Early Detection Of Cancer ◽  
Cancer Biomarkers ◽  
Diagnostic Tools ◽  
Detection Systems ◽  
Highly Sensitive ◽  
Current Detection ◽  
Insufficient Sensitivity

Abstract Biomarkers are emerging as potentially important diagnostic tools for cancer and many other diseases. However, many current detection systems for suffer from insufficient sensitivity. To address this concern, we developed a highly sensitive biosensor, featuring monoclonal antibody-coated polystyrene nanobeads assembled in the trenches of a microchip, for the detection of cancer biomarkers. These biosensors detected nucleosomes and carcinoembryonic antigen in serum at concentrations of 62.5 and 15.6 pg/mL, respectively. Very low detection limits that suggest such devices might be beneficial for the early detection of tumors and for monitoring of patients in remission.

Electrochemiluminescence detection for development of immunoassays and DNA probe assays for clinical diagnostics

1991 ◽  
Vol 37 (9) ◽  
pp. 1534-1539 ◽  
Author(s):  
G F Blackburn ◽  
H P Shah ◽  
J H Kenten ◽  
J Leland ◽  
R A Kamin ◽  
...  
Keyword(s):  
Small Molecules ◽  
Dynamic Range ◽  
New Technology ◽  
Clinical Diagnostics ◽  
Reaction Products ◽  
Large Molecules ◽  
Detection Systems ◽  
Highly Sensitive ◽  
Polymerase Chain ◽  
Set Up

Abstract Electrochemiluminescence (ECL) has been developed as a highly sensitive process in which reactive species are generated from stable precursors (i.e., the ECL-active label) at the surface of an electrode. This new technology has many distinct advantages over other detection systems: no radioisotopes are used; detection limits for label are extremely low (200 fmol/L); the dynamic range for label quantification extends over six orders of magnitude; the labels are extremely stable compared with those of most other chemiluminescent systems; the labels, small molecules (approximately 1000 Da), can be used to label haptens or large molecules, and multiple labels can be coupled to proteins or oligonucleotides without affecting immunoreactivity, solubility, or ability to hybridize; because the chemiluminescence is initiated electrochemically, selectivity of bound and unbound fractions can be based on the ability of labeled species to access the electrode surface, so that both separation and nonseparation assays can be set up; and measurement is simple and rapid, requiring only a few seconds. We illustrate ECL in nonseparation immunoassays for digoxin and thyrotropin and in separation immunoassays for carcinoembryonic antigen and alpha-fetoprotein. The application of ECL for detection of polymerase chain reaction products is described and exemplified by quantifying the HIV1 gag gene.

scholarly journals SARS-CoV-2 multi-variant graphene biosensor based on engineered dimeric ACE2 receptor

2021 ◽  
Author(s):  
Mattia D'Agostino ◽  
Eleonora Pavoni ◽  
Alice Romagnoli ◽  
Chiara Ardiccioni ◽  
Stefano Motta ◽  
...  
Keyword(s):  
Point Of Care ◽  
Host Cells ◽  
Clinical Samples ◽  
Detection Systems ◽  
Graphene Field Effect Transistor ◽  
Highly Sensitive ◽  
Care Systems ◽  
Point Of Care Systems ◽  
Computational Analyses

Fast, reliable and point-of-care systems to detect the SARS-CoV-2 infection are crucial to contain viral spreading and to adopt timely clinical treatments. Many of the rapid detection tests currently in use are based on antibodies that bind viral proteins. However, newly appearing virus variants accumulate mutations in their RNA sequence and produce proteins, such as Spike, that may show reduced binding affinity to these diagnostic antibodies, resulting in less reliable tests and in the need for continuous update of the sensing systems. Here we propose a graphene field-effect transistor (gFET) biosensor which exploits the key interaction between the Spike protein and the human ACE2 receptor. This interaction is one of the determinants of host infections and indeed recently evolved Spike variants were shown to increase affinity for this receptor. Through extensive computational analyses we show that a chimeric ACE2-Fc construct mimics the ACE2 dimer, normally present on host cells membranes, better than its soluble truncated form. We demonstrate that ACE2-Fc functionalized gFET is effective for in vitro detection of Spike and outperforms the same chip functionalized with either a diagnostic antibody or the soluble ACE2. Our sensor is implemented in a portable, wireless, point-of-care device and successfully detected both alpha and gamma virus variants in patient clinical samples. As incomplete immunization, due to vaccine roll-out, may offer new selective grounds for antibody-escaping virus variants, our biosensor opens to a class of highly sensitive and variant-robust SARS-CoV-2 detection systems.

Selected subassemblies of infrared heterodyne detection systems

1997 ◽  
Author(s):  
Marek Strzelec ◽  
Zbigniew Puzewicz ◽  
Miroslaw Kopica
Keyword(s):  
Heterodyne Detection ◽  
Detection Systems

scholarly journals Development of a correlation ECE radiometer for electron temperature fluctuation measurements in Heliotron J

2019 ◽  
Vol 203 ◽  
pp. 03013
Author(s):  
Gavin M. Weir ◽  
Kazunobu Nagasaki ◽  
Jinxiang Zhu ◽  
Maoyuan Luo ◽  
Hiroyuki Okada ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Temperature Fluctuation ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Intermediate Frequency ◽  
Local Oscillator ◽  
Heterodyne Detection ◽  
Helical Axis ◽  
Detection Systems ◽  
Heating Radiation

A radial correlation ECE radiometer diagnostic has been developed for electron temperature fluctuation measurements in the helical-axis heliotron device, Heliotron J. The radiometer consists of two heterodyne detection systems. One system scans the frequency of a local oscillator from 52 to 64 GHz with a single intermediate frequency filter, and the second system has a fixed frequency, 56 GHz local oscillator with four intermediate frequency filters. This frequency range covers measurement positions spanning from the plasma core to the half radius. Laboratory tests indicate that each system has narrow intermediate frequency bandwidth and high-sensitivity over a large dynamic range. During plasma experiments with NBI heating, radiation temperature fluctuation measured by the CECE radiometer decrease with increasing ECCD commensurate with previous measurements of energetic particle driven modes on Heliotron J.

scholarly journals Stokes dual-soliton spectroscopy in a graphene functionalized over-modal microresonator

2021 ◽  
Author(s):  
Giancarlo Soavi ◽  
Zhongye Yuan ◽  
Teng Tan ◽  
Guofeng Yan ◽  
Siyu Zhou ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Chemical Species ◽  
Transverse Mode ◽  
Photonic Devices ◽  
Heterodyne Detection ◽  
Detection Scheme ◽  
Biochemical Sensing ◽  
Highly Sensitive ◽  
Spectral Ranges ◽  
First Time

Abstract Dual comb spectroscopy enables fast and accurate measurements over broad spectral ranges, offering a powerful tool to identify chemical species with unprecedented spectral resolution. Co-generation of soliton combs in one single microresonator can be used to improve the compactness of multi-comb sources and bridge the lab-to-fab gap. However, the robustness of pristine microresonators to environmental changes limits their potential in broader applications such as biochemical sensing. Here, we realize for the first time a two-dimensional-material functionalized dual-comb spectrometer by asymmetrically depositing graphene in an over-modal microsphere. Spectrally trapped Stokes solitons belonging to distinct transverse mode families are co-generated in one single device. A soliton mode in the graphene-functionalized region is highly sensitive to environmental changes while a second soliton mode in the pristine region serves as reference, thus producing dual-comb ultrasensitive beat notes in the electrical domain. Taking advantage of an advanced optoelectronic heterodyne detection scheme, we trace the frequency shift of the dual-soliton beat-note with uncertainty < 0.2 Hz and we achieve real-time individual gas molecule detection in vacuum. This combination of atomically thin materials and microcombs shows the potential for integrated spectroscopy with unprecedented performances and offers new insights toward the design of versatile functionalized microcavity photonic devices.

scholarly journals BLOCK DIAGRAM OF A MULTI-FREQUENCY RADIOMETRIC COMPLEX FOR UAV DETECTION IN DIFFERENT METEOROLOGICAL CONDITIONS

2021 ◽  
pp. 50-57
Author(s):  
Nikolay Ruzhentsev ◽  
Simeon Zhyla ◽  
Vladimir Pavlikov ◽  
Gleb Cherepnin ◽  
Eduard Tserne ◽  
...  
Keyword(s):  
Thermal Radiation ◽  
Traffic Control ◽  
Block Diagram ◽  
Meteorological Conditions ◽  
Measurement Systems ◽  
Detection Systems ◽  
Cloudy Atmosphere ◽  
Highly Sensitive ◽  
Terrorist Acts ◽  
And Control

Background. Technologies for the production of unmanned aerial vehicles (UAVs) of various classes are rapidly developing in Ukraine and the world. Small in terms of weight and dimensions and almost invisible for most information and measurement systems, UAVs began to be used in various industries - from the national economy to multimedia and advertising. Together with their useful application, new dangers and incidents have appeared - a collision of UAVs with people, structures, cultural monuments, the transportation of criminal goods, terrorist acts, flights over prohibited areas and within airports. UAV detection and control of their movement in populated areas and near critical objects are becoming one of the most important tasks of air traffic control services. The existing systems of the optical, acoustic and radar ranges cannot effectively perform such tasks in difficult meteorological conditions. As an addition to the already developed detection systems, it is proposed to use radiometric systems that register the UAV's own radio-thermal radiation. The authors have developed the theoretical foundations for the construction of multifrequency complexes necessary for the specification of their structural schemes. Objective. The purpose of the paper is development of a scheme for a multi-frequency radiometric complex for detecting UAVs in different meteorological conditions based on optimal algorithms. Methods. Analysis of the experience in the development of radiometric systems and methods for dealing with fluctuations in the gain of receivers, optimal operations for processing signals of intrinsic radio-thermal radiation, investigations of the probabilistic characteristics of detection and analysis of the domestic market of microwave technology developers will make it possible to develop a scheme of a multifrequency radiometric complex that will perform reliable measurements in various meteorological conditions. Results. A block diagram of a four-frequency radiometric complex is proposed, which can be implemented in practice and is capable of performing reliable measurements in various meteorological conditions. The frequencies 10 GHz, 20 GHz, 35 GHz, and 94 GHz were chosen as the resonant frequencies for tuning the radiometric receivers. For a given design and characteristics of receivers, the probabilities of detecting a UAV were calculated depending on the range of its flight. Conclusions. From the results of the analysis of the existing achievements in the development of radiometric systems in Ukraine and the elemental base of microwave components available on the market, it follows that the Ku and K bands have the worst characteristics of spatial resolution, but are all-weather. The Ka and W bands are highly sensitive to radio-thermal radiation against the background of a clear sky, but are completely "blind" in a cloudy atmosphere and in rain. The results of calculating the detection ranges with a probability of 0.9 lie in the range from 1 to 3 km, depending on the condition of the atmosphere. These results coincide with the known detection ranges of optical, acoustic and radar systems, but the selected parameters of the receivers do not correspond to potential world achievements and can be improved.

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