Search NASA⌕ Search

SEARCH · Search NASA

Results for “signal amplification”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Magnetic Particle-Based Immunoassay of Phosphorylated p53 Using Protein-Cage Templated Lead Phosphate and Carbon Nanospheres for Signal Amplification

Phosphorylated p53 at serin 15 (phospho-p53-15) is a potential biomarker of Gamma-radiation exposure. In this paper, we described a new magnetic particles (MPs)-based electrochemical immunoassay of human phospho-p53-15 using carbon nanospheres (CNS) and protein-cage templated lead phosphate nanoparticles for signal amplification. Greatly enhanced sensitivity was achieved by three aspects: 1) The protein-cage nanoparticle (PCN) and p53-15 signal antibody (p53-15 Ab2) are linked to CNS (PCNof each apoferritin; 3) MPs capture a large amount of primary antibodies. Using apoferritin templated metallic phosphate instead of enzyme as label has the advantage of eliminating the addition of mediator or immunoreagents and thus makes the immunoassay system simpler. The subsequent stripping voltammetric analysis of the released lead ions were detected on a disposable screen printed electrode. The response current was proportional to the phospho-p53-15 concentration in the range of 0.02 to 20 ng mL-1 with detection limit of 0.01 ng mL-1. This method shows a good stability, reproducibility and recovery.

Environmental Molecular Sciences Laboratory↗
DOE OSTI2015

Cycling excitation process: An ultra efficient and quiet signal amplification mechanism in semiconductor

Signal amplification, performed by transistor amplifiers with its merit rated by the efficiency and noise characteristics, is ubiquitous in all electronic systems. Because of transistor thermal noise, an intrinsic signal amplification mechanism, impact ionization was sought after to complement the limits of transistor amplifiers. However, due to the high operation voltage (30-200 V typically), low power efficiency, limited scalability, and, above all, rapidly increasing excess noise with amplification factor, impact ionization has been out of favor for most electronic systems except for a few applications such as avalanche photodetectors and single-photon Geiger detectors. Here, we report an internal signal amplification mechanism based on the principle of the phonon-assisted cycling excitation process (CEP). Si devices using this concept show ultrahigh gain, low operation voltage, CMOS compatibility, and, above all, quantum limit noise performance that is 30 times lower than devices using impact ionization. Established on a unique physical effect of attractive properties, CEP-based devices can potentially revolutionize the fields of semiconductor electronics.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2018

Arrestin-3 scaffolding of the JNK3 cascade suggests a mechanism for signal amplification

Significance Scaffold proteins are key regulators of signal transduction that bind multiple proteins of a signaling pathway. This simple tethering model explains how the scaffold colocalizes the components for signal propagation, but it is unclear whether scaffolds ensure signal amplification. Here, we use arrestin-3 and the ASK1-MKK4/7-JNK3 kinase cascade as a model system to explore whether scaffolding amplifies signaling. Our studies suggest a model of scaffold-dependent signal amplification that may be conceptually applicable to other scaffold-dependent signaling pathways.

Perry, Nicole A.↗
DOE OSTI2014

Eight-fold signal amplification of a superconducting nanowire single-photon detector using a multiple-avalanche architecture

Superconducting nanowire avalanche single-photon detectors (SNAPs) with n parallel nanowires are advantageous over single-nanowire detectors because their output signal amplitude scales linearly with n. However, the SNAP architecture has not been viably demonstrated for n > 4. To increase n for larger signal amplification, we designed a multi-stage, successive-avalanche architecture which used nanowires, connected via choke inductors in a binary-tree layout. We demonstrated an avalanche detector with n = 8 parallel nanowires and achieved eight-fold signal amplification, with a timing jitter of 54 ps.

47 OTHER INSTRUMENTATION↗
DOE OSTI2025

Signal amplification in a solid-state sensor through asymmetric many-body echo

Electronic spins of nitrogen–vacancy centres in diamond constitute a promising system for micro- and nanoscale magnetic sensing, because of their operation under ambient conditions, ease of placement in close proximity to sensing targets and biological compatibility. At high densities, the electronic spins interact through dipolar coupling, which typically limits but can also potentially enhance sensing performance. Here we report the experimental demonstration of many-body signal amplification in a solid-state, room-temperature quantum sensor. Our approach uses time-reversed two-axis-twisting interactions, engineered through dynamical control of the quantization axis and Floquet engineering in a two-dimensional ensemble of nitrogen–vacancy centres. We observe that optimal amplification occurs when the backward evolution time equals twice the forward evolution time, in sharp contrast to the conventional Loschmidt echo. These observations can be understood as resulting from an underlying time-reversed mirror symmetry of the microscopic dynamics, providing key insights into signal amplification and opportunities for practical entanglement-enhanced quantum sensing.

quantum information↗
DOE OSTI2015

Polygold‐FISH for signal amplification of metallo‐labeled microbial cells

An improved in situ hybridization approach (Polygold‐FISH) using biotinylated probes targeting multiple locations of the 16 S ribosomal subunit, followed by fluoronanogold‐streptavidin labeling and autometallographic enhancement of nanogold particles was developed as a means of signal amplification of metallo‐labeled cells, without the need for Catalyzed Reporter Deposition (CARD). Bacterial cells were readily detected based on their gold‐particle signal using scanning‐electron microscopy and energy‐dispersive X‐ray spectroscopy when contrasted with controls or cells hybridized with a single probe. Polygold‐FISH presents an alternative to CARD‐FISH, circumventing the need for aggressive oxidants, which is useful when products of microbial respiration such as those relevant at the microbe‐mineral interface could be altered during processing for visualization.

Almstrand, Robert↗
DOE OSTI2026

Cryogenic light detectors with thermal signal amplification for 0 νββ search experiments

As a step towards the realization of cryogenic-detector experiments to search for neutrinoless double-beta decay (such as CROSS, BINGO, and CUPID), we investigated a batch of 10 Ge light detectors (LDs) assisted by Neganov-Trofimov-Luke (NTL) signal amplification. Each LD was assembled with a large cubic light-emitting crystal (45 mm side) using the recently developed CROSS mechanical structure. The detector array was operated at milli-Kelvin temperatures in a pulse-tube cryostat at the Canfranc underground laboratory in Spain. We achieved good performance with scintillating bolometers from CROSS, made of Li 2 100 MoO 4 crystals and used as reference detectors of the setup, and with all LDs tested (except for a single device that encountered an electronics issue). No leakage current was observed for 8 LDs with an electrode bias up to 100 V. Operating the LDs at an 80 V electrode bias applied in parallel, we obtained a gain of around 9 in the signal-to-noise ratio of these devices, allowing us to achieve a baseline noise RMS of O(10 eV). Thanks to the strong current polarization of the temperature sensors, the time response of the devices was reduced to around half a millisecond in rise time. The achieved performance of the LDs was extrapolated via simulations of pile-up rejection capability for several configurations of the CUPID detector structure. Despite the sub-optimal noise conditions of the LDs (particularly at high frequencies), we demonstrated that the NTL technology provides a viable solution for background reduction in CUPID.

47 OTHER INSTRUMENTATION↗
DOE OSTI2017

An Enzyme-Free Signal Amplification Technique for Ultrasensitive Colorimetric Assay of Disease Biomarkers

Enzyme-based colorimetric assays have been widely used in research labs and clinical diagnosis for decades. Nevertheless, as constrained by the performance of enzymes, their detection sensitivity has not been substantially improved in recent years, which inhibits many critical applications such as early detection of cancers. In this work, we demonstrate an enzyme-free signal amplification technique, based on gold vesicles encapsulated with Pd-Ir nanoparticles as peroxidase mimics, for colorimetric assay of disease biomarkers with significantly enhanced sensitivity. This technique overcomes the intrinsic limitations of enzymes, thanks to the superior catalytic efficiency of peroxidase mimics and the efficient loading and release of these mimics. Using human prostate surface antigen as a model biomarker, we demonstrated that the enzyme-free assay could reach a limit of detection at the femtogram/mL level, which is over 10 3 -fold lower than that of conventional enzyme-based assay when the same antibodies and similar procedure were used.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS2006

Nonenzymatic catalytic signal amplification for nucleic acid hybridization assays

Devices, methods, and kits for amplifying the signal from hybridization reactions between nucleic acid probes and their cognate targets are presented. The devices provide partially-duplexed, immobilized probe complexes, spatially separate from and separately addressable from immobilized docking strands. Cognate target acts catalytically to transfer probe from the site of probe complex immobilization to the site of immobilized docking strand, generating a detectable signal. The methods and kits of the present invention may be used to identify the presence of cognate target in a fluid sample.

Fan, Wenhong↗
NASA NTRS1989

Direct solar-pumped iodine laser amplifier

This semiannual progress report covers the period from September 1, 1988 to February 28, 1989 under NASA grant NAG-1-441 entitled, Direct Solar-Pumped Iodine Laser Amplifier. During this period, the research effort was concentrated on the solar pumped master oscillator power amplifier (MOPA) system using n-C3F7I. In the experimental work, the amplification measurement was conducted to identify the optimum conditions for amplification of the center's Vortek solar simulator pumped iodine laser amplifier. A modeling effort was also pursued to explain the experimental results in the theoretical work. The amplification measurement of the solar simulator pumped iodine laser amplifier is the first amplification experiment on the continuously pumped amplifier. The small signal amplification of 5 was achieved for the triple pass geometry of the 15 cm long solar simulator pumped amplifier at the n-C3F7I pressure of 20 torr, at the flow velocity of 6 m/sec and at the pumping intensity of 1500 solar constants. The XeCl laser pumped iodine laser oscillator, which was developed in the previous research, was employed as the master oscillator for the amplification measurement. In the theoretical work, the rate equations of the amplifier was established and the small signal amplification was calculated for the solar simulator pumped iodine laser amplifier. The amplification calculated from the kinetic equations with the previously measured rate coefficients reveals very large disagreement with experimental measurement. Moreover, the optimum condition predicted by the kinetic equation is quite discrepant with that measured by experiment. This fact indicates the necessity of study in the measurement of rate coefficients of the continuously pumped iodine laser system.

Han, Kwang S.↗
DOE OSTI2015

Electrochemical Sensors and Biosensors Based on Nanomaterials and Nanostructures

Taking advantages of exceptional attributes, such as easy-to-operate, economical, sensitive, portable, and simple-to- construct, considerable attention has been devoted to the integration of recognition elements with electronic elements to develop electrochemical sensors and biosensors. Recent decades tremendous amounts of attention have been witnessed in this active area. Various electrochemical devices such as amperometric sensors, electrochemical impedance sensors, electrochemical luminescence sensors as well as photoelectrochemical sensors, provide wide applications of detecting chemical and biological targets in terms of electrochemical change of electrode interfaces. With remarkable achievements in nanotechnology and nanoscience, nanomaterial-based electrochemical signal amplifications have great potential of improving both in sensitivity and selectivity for electrochemical sensors and biosensors. First of all, it is well known that the electrode materials play a critical role in the construction of high-performance electrochemical sensing platforms for detecting target molecules through various analytical principles. Furthermore, in addition to electrode materials, functional nanomaterials can not only produce a synergic effect among catalytic activity, conductivity and biocompatibility to accelerate the signal transduction, but also amplify biorecognition events by specifically designed signal tags, leading to highly sensitive biosensing. Sig-nificantly, extensive research on construction of functional electrode materials, coupled with numerous electrochemical methods, is advancing wide applications of electrochemical devices. For example, Walcarius et al. highlighted the recent advances of nano-objects, nano-engineered and/or nanostructured materials for the rational design of bio-functionalized electrodes and related (bio)sensing systems.1 The attractiveness of such nanomaterials relies on their ability to act as effective immobilization matrices, and their intrinsic and unique features as described above. These features combined with the functioning of biomolecules contribute to the improvement of bioelectrode performance in terms of sensitivity and specificity. Our group recently presented a general overview of nanomaterial-enhanced paper-based biosensors including lateral-flow test-strip, and paper microfluidic devices.2With different kinds of nanoparticles (NPs), paper-based biosensor devices have shown great potential in the enhancement of sensitivity and specificity of disease diagnosis in developing countries. This review focuses on recent advances in electrochemical sensors and biosensors based on nanomaterials and nanostructures during 2013 to 2014. The aim of this effort is to provide the reader with a clear and concise view of new advances in areas ranging from electrode engineering, strategies for electrochemical signal amplification, and novel electroanalytical techniques used to the miniaturization and integration of the sensors. Moreover, the authors have attempted to highlight areas of latest and significant development of enhanced elec-trochemical nanosensors and nanobiosensors that inspire broader interests across various disciplines. Electrochemical sensors for small molecules, enzyme-based biosensors, genosensors, immunosensors and cytosensors are reviewed herein (Figure 1). Such novel advances are important for the development of electrochemical sensors as that open up new avenues and methods for future research. Readers interested in the general principles of electrochemical sensors and electrochemical methods are recommended to refer to other excellent literature for a broad scope on this area.3-4 However, due to the explosion of publications in this active field, we do not claim that this review includes all of the published works in the past two years. Due to the large activity in this field we apologize to the authors of excellent work, which is unintentionally left out.

Zhu, Chengzhou↗