scholarly journals Comparing current noise in biological and solid-state nanopores

2019 ◽  
Author(s):  
A. Fragasso ◽  
S. Schmid ◽  
C. Dekker
Keyword(s):  
Solid State ◽  
Single Molecule ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Ionic Current ◽  
Low Noise ◽  
Signal To Noise ◽  
Experimental Conditions ◽  
High Frequencies ◽  
Noise Ratio

AbstractNanopores bear great potential as single-molecule tools for bioanalytical sensing and sequencing, due to their exceptional sensing capabilities, high-throughput, and low cost. The detection principle relies on detecting small differences in the ionic current as biomolecules traverse the nanopore. A major bottleneck for the further progress of this technology is the noise that is present in the ionic current recordings, because it limits the signal-to-noise ratio and thereby the effective time resolution of the experiment. Here, we review the main types of noise at low and high frequencies and discuss the underlying physics. Moreover, we compare biological and solid-state nanopores in terms of the signal-to-noise ratio (SNR), the important figure of merit, by measuring free translocations of a short ssDNA through a selected set of nanopores under typical experimental conditions. We find that SiNx solid-state nanopores provide the highest SNR, due to the large currents at which they can be operated and the relatively low noise at high frequencies. However, the real game-changer for many applications is a controlled slowdown of the translocation speed, which for MspA was shown to increase the SNR >160-fold. Finally, we discuss practical approaches for lowering the noise for optimal experimental performance and further development of the nanopore technology.

Internally Modulated Chirped Pulse Based Direct Detection Type φ-OTDR System with High Signal-to-Noise Ratio and Low Cost

2019 ◽  
Vol 46 (8) ◽  
pp. 0806003
Author(s):  
李鲁川 Luchuan Li ◽  
卢斌 Bin Lu ◽  
王校 Xiao Wang ◽  
梁嘉靖 Jiajing Liang ◽  
郑汉荣 Hanrong Zheng ◽  
...  
Keyword(s):  
Direct Detection ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
High Signal ◽  
Signal To Noise ◽  
Chirped Pulse ◽  
Noise Ratio

The Noise Analysis of Fluid Systemsin Solid-State Nanopore Sensors

2013 ◽  
Vol 419 ◽  
pp. 517-520 ◽  
Author(s):  
Song Ying ◽  
Lei Wang ◽  
Wen Yuan Zhao
Keyword(s):  
Solid State ◽  
Signal To Noise Ratio ◽  
Noise Analysis ◽  
Power Spectra ◽  
Noise Power ◽  
Label Free ◽  
Signal To Noise ◽  
Fluid Systems ◽  
Noise Ratio ◽  
Nanopore Sensors

The solid-state nanopore sensor offers a versatile platform for the rapid, label-free electrical detection and analysis of single molecules, especially on DNA sequencing. However, the overall signal-to-noise ratio (SNA) is a major challenge in sequencing applications. In our work, two different fluid systems made by metal and plexiglass have been designed to improve the signal to noise ratio of the solid-state nanopore sensor. From the measurements on the noise power spectra with a variety of conditions, it is found that plexiglass fluid system coupled with shielding box produces a good quality of electric signals on nanopore sensors.

Magnetoelectric Sensors With Directly Integrated Charge Sensitive Readout Circuit—Improved Field Sensitivity and Signal-to-Noise Ratio

2011 ◽  
Vol 11 (10) ◽  
pp. 2260-2265 ◽  
Author(s):  
Zhao Fang ◽  
Ninad Mokhariwale ◽  
Feng Li ◽  
Suman Datta ◽  
Q. M. Zhang
Keyword(s):  
Room Temperature ◽  
Signal To Noise Ratio ◽  
Low Noise ◽  
Magnetic Sensors ◽  
Readout Circuit ◽  
Signal To Noise ◽  
Low Frequencies ◽  
Field Sensitivity ◽  
Piezoelectric Layers ◽  
Noise Ratio

The large magnetoelectric (ME) coupling in the ME laminates makes them attractive for ultrasensitive room temperature magnetic sensors. Here ,we investigate the field sensitivity and signal-to-noise ratio (SNR) of ME laminates, consisting of magnetostrictive and piezoelectric layers (Metglas and piezopolymer PVDF were used as the model system), which are directly integrated with a low noise readout circuit. Both the theoretical analysis and experimental results show that increasing the number of piezoelectric layers can improve the SNR, especially at low frequencies. We also introduce a figure of merit to measure the overall influence of the piezolayer properties on the SNR and show that the newly developed piezoelectric single crystals of PMN-PT and PZN-PT have the promise to achieve a very high SNR and consequently ultra-high sensitivity room temperature magnetic sensors. The results show that the ME coefficients used in early ME composites development works may not be relevant to the SNR. The results also show that enhancing the magnetostrictive coefficient, for example, by employing the flux concentration effect, can lead to enhanced SNR.

scholarly journals Improving the Signal to Noise Ratio of QTF Preamplifiers Dedicated for QEPAS Applications

2020 ◽  
Vol 10 (12) ◽  
pp. 4105
Author(s):  
Piotr Z. Wieczorek ◽  
Tomasz Starecki ◽  
Frank K. Tittel
Keyword(s):  
Operational Amplifier ◽  
Narrow Band ◽  
Signal To Noise Ratio ◽  
Low Frequency ◽  
Electrical Signal ◽  
Low Noise ◽  
Detection Sensitivity ◽  
Noise Amplitude ◽  
Signal To Noise ◽  
Noise Ratio

The signal-to-noise ratio (SNR) is a major factor that limits the detection sensitivity of quartz-enhanced photoacoustic spectroscopy (QEPAS) sensors. The higher the electrical signal level compared to the noise amplitude is the lower the concentration of gases that can be detected. For this reason the preamplifier circuits used in QEPAS should be optimized for low-frequency narrow-band applications. Moreover, special care should be taken when choosing a particular operational amplifier in either a transimpedance or voltage (differential) configuration. It turns out that depending on the preamp topology different operational amplifier parameters should be carefully considered when a high SNR of the whole QEPAS system is required. In this article we analyzed the influence of the crucial parameters of low-noise operational preamplifiers used in QEPAS applications and show the resulting limitations of transimpedance and voltage configurations.

scholarly journals A mobile seismograph array

1966 ◽  
Vol 56 (4) ◽  
pp. 889-897 ◽  
Author(s):  
Francis E. Lehner ◽  
Frank Press
Keyword(s):  
Solid State ◽  
Frequency Band ◽  
Magnetic Tape ◽  
Signal To Noise Ratio ◽  
Tape Recording ◽  
Signal To Noise ◽  
Internal Calibration ◽  
Noise Ratio ◽  
High Degree ◽  
Installation Time

abstract A movable array composed of Ranger type seismometers, 60-day film recorders and 7-day magnetic tape recorders housed in compact trailers, has been developed. The array is useful for research requiring frequent instrument relocation such as P-delay, micro-seismicity, aftershock and signal-to-noise ratio studies. The array unit combines the functions found in conventional fixed stations with a high degree of mobility. Conveniences such as solid state amplifiers, radio and clock circuitry, internal calibration, and minimum installation time are special features. With the battery supply provided, a one week period of unattended film and tape recording is possible. With commercial power, the instruments can operate unattended for up to sixty days. Useful magnification up to several million is available, depending on the frequency band selected.

scholarly journals Single-molecule optical absorption imaging by nanomechanical photothermal sensing

2018 ◽  
Vol 115 (44) ◽  
pp. 11150-11155 ◽  
Author(s):  
Miao-Hsuan Chien ◽  
Mario Brameshuber ◽  
Benedikt K. Rossboth ◽  
Gerhard J. Schütz ◽  
Silvan Schmid
Keyword(s):  
Single Molecule ◽  
Shot Noise ◽  
Signal To Noise Ratio ◽  
Local Heating ◽  
Single Molecules ◽  
High Sensitivity ◽  
Temperature Sensitive ◽  
Signal To Noise ◽  
Promising Alternative ◽  
Noise Ratio

Absorption microscopy is a promising alternative to fluorescence microscopy for single-molecule imaging. So far, molecular absorption has been probed optically via the attenuation of a probing laser or via photothermal effects. The sensitivity of optical probing is not only restricted by background scattering but it is fundamentally limited by laser shot noise, which minimizes the achievable single-molecule signal-to-noise ratio. Here, we present nanomechanical photothermal microscopy, which overcomes the scattering and shot-noise limit by detecting the photothermal heating of the sample directly with a temperature-sensitive substrate. We use nanomechanical silicon nitride drums, whose resonant frequency detunes with local heating. Individual Au nanoparticles with diameters from 10 to 200 nm and single molecules (Atto 633) are scanned with a heating laser with a peak irradiance of 354 ± 45 µW/µm2 using 50× long-working-distance objective. With a stress-optimized drum we reach a sensitivity of 16 fW/Hz1/2 at room temperature, resulting in a single-molecule signal-to-noise ratio of >70. The high sensitivity combined with the inherent wavelength independence of the nanomechanical sensor presents a competitive alternative to established tools for the analysis and localization of nonfluorescent single molecules and nanoparticles.

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