scholarly journals Strategy toward Miniaturized, Self-out-Readable Resonant Cantilever and Integrated Electrostatic Microchannel Separator for Highly Sensitive Airborne Nanoparticle Detection

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 901 ◽  
Author(s):  
Maik Bertke ◽  
Jiushuai Xu ◽  
Michael Fahrbach ◽  
Andi Setiono ◽  
Hutomo Wasisto ◽  
...  
Keyword(s):  
Particle Separation ◽  
Signal Amplitude ◽  
Resonance Mode ◽  
Nanoelectromechanical Systems ◽  
Nanoparticle Detection ◽  
Highly Sensitive ◽  
Real Time Tracking ◽  
Monitoring Devices ◽  
Theoretical Sensitivity ◽  
Airborne Nanoparticle

In this paper, a self-out-readable, miniaturized cantilever resonator for highly sensitive airborne nanoparticle (NP) detection is presented. The cantilever, which is operated in the fundamental in-plane resonance mode, is used as a microbalance with femtogram resolution. To maximize sensitivity and read-out signal amplitude of the piezo-resistive Wheatstone half bridge, the geometric parameters of the sensor design are optimized by finite element modelling (FEM). The electrical read-out of the cantilever movement is realized by piezo-resistive struts at the sides of the cantilever resonator that enable real-time tracking using a phase-locked loop (PLL) circuit. Cantilevers with minimum resonator mass of 1.72 ng and resonance frequency of ~440 kHz were fabricated, providing a theoretical sensitivity of 7.8 fg/Hz. In addition, for electrostatic NP collection, the cantilever has a negative-biased electrode located at its free end. Moreover, the counter-electrode surrounding the cantilever and a µ-channel, guiding the particle-laden air flow towards the cantilever, are integrated with the sensor chip. µ-channels and varying sampling voltages will also be used to accomplish particle separation for size-selective NP detection. To sum up, the presented airborne NP sensor is expected to demonstrate significant improvements in the field of handheld, micro-/nanoelectromechanical systems (M/NEMS)-based NP monitoring devices.

scholarly journals Design of Miniaturized, Self-Out-Readable Cantilever Resonator for Highly Sensitive Airborne Nanoparticle Detection

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 879
Author(s):  
Maik Bertke ◽  
Jiushuai Xu ◽  
Michael Fahrbach ◽  
Andi Setiono ◽  
Gerry Hamdana ◽  
...  
Keyword(s):  
Rest Mass ◽  
Particle Separation ◽  
Optimized Design ◽  
Nanoparticle Detection ◽  
Highly Sensitive ◽  
Measurement Signal ◽  
Monitoring Devices ◽  
Theoretical Sensitivity ◽  
Maximum Measurement ◽  
Airborne Nanoparticle

In this paper, a self-out-readable, miniaturized cantilever resonator for highly sensitiveairborne nanoparticle (NP) detection is presented. The cantilever, which is operated in thefundamental in-plane resonance mode, is used as a microbalance with femtogram resolution. Toachieve a maximum measurement signal of the piezo resistive Wheatstone half-bridge, thegeometric parameters of the sensor design were optimized by finite element modelling (FEM).Struts at the sides of the cantilever resonator act as piezo resistors and enable an electrical read-outof the phase information of the cantilever movement whereby they do not contribute to theresonators rest mass. For the optimized design, a resonator mass of 0.93 ng, a resonance frequencyof ~440 kHz, and thus a theoretical sensitivity of 4.23 fg/Hz can be achieved. A μ-channel guiding aparticle-laden air flow towards the cantilever is integrated into the sensor chip. Electrically chargedNPs will be collected by an electrostatic field between the cantilever and a counter-electrode at theedges of the μ-channel. Such μ-channels will also be used to accomplish particle separation for sizeselectiveNP detection. Throughout, the presented airborne NP sensor is expected to demonstratesignificant improvements in the field of handheld, MEMS-based NP monitoring devices.

scholarly journals Self-reading femtogram microbalance for highly sensitive airborne nanoparticle detection

2019 ◽  
Vol 1319 ◽  
pp. 012004
Author(s):  
M Bertke ◽  
J Xu ◽  
A Setiono ◽  
G Hamdana ◽  
H S Wasisto ◽  
...  
Keyword(s):  
Nanoparticle Detection ◽  
Highly Sensitive ◽  
Airborne Nanoparticle

FeMn layered double hydroxides: an efficient bifunctional electrocatalyst for real-time tracking of cysteine in whole blood and dopamine in biological samples

2020 ◽  
Vol 8 (36) ◽  
pp. 8249-8260
Author(s):  
Muthaiah Annalakshmi ◽  
Sakthivel Kumaravel ◽  
Shen-Ming Chen ◽  
Tse-Wei Chen
Keyword(s):  
Real Time ◽  
Layered Double Hydroxides ◽  
Biological Samples ◽  
Whole Blood ◽  
Sensitive Detection ◽  
Bifunctional Electrocatalyst ◽  
Highly Sensitive ◽  
Real Time Tracking ◽  
Highly Sensitive Detection ◽  
Double Hydroxides

A peculiar clock-regulated design of FeMn-LDHs (FMH) with specific physiochemical attributes has been developed and used for highly sensitive detection of cysteine (CySH) and dopamine (DA).

scholarly journals Nitrogen Dioxide Selective Sensor for Humid Environments Based on Octahedral Indium Oxide

2021 ◽  
Vol 2 ◽  
Author(s):  
Guillem Domènech-Gil ◽  
Isabel Gràcia ◽  
Carles Cané ◽  
Albert Romano-Rodríguez
Keyword(s):  
Gas Sensors ◽  
Cost Effective ◽  
Air Quality Monitoring ◽  
Outdoor Air ◽  
Promising Candidate ◽  
Post Process ◽  
Highly Sensitive ◽  
Monitoring Devices ◽  
Indoor And Outdoor ◽  
Selective Sensor

We report the growth of micrometer-sized In2O3 octahedral structures, which are next aligned in chains using dielectrophoresis on top of microhotplates with prepatterned electrodes and integrated heater to work as chemoresistive gas sensors. The devices are relatively fast (180 s), highly sensitive (response up to ~256%), and selective toward NO2 in humid environments, showing little response to O2 and ethanol, and being completely insensitive to CO and CH4. The here-presented fabrication method can be easily extended as a cost-effective post-process in CMOS-compatible microhotplate fabrication and, thus, represents a promising candidate for indoor and outdoor air quality monitoring devices.

scholarly journals Airborne Nanoparticle Detection By Sampling On Filters And Laser-Induced Breakdown Spectroscopy Analysis

2011 ◽  
Vol 304 ◽  
pp. 012012 ◽  
Author(s):  
Pascale Dewalle ◽  
Jean-Baptiste Sirven ◽  
Audrey Roynette ◽  
François Gensdarmes ◽  
Luana Golanski ◽  
...  
Keyword(s):  
Laser Induced Breakdown Spectroscopy ◽  
Spectroscopy Analysis ◽  
Breakdown Spectroscopy ◽  
Nanoparticle Detection ◽  
Laser Induced Breakdown ◽  
Airborne Nanoparticle

scholarly journals Real-time single airborne nanoparticle detection with nanomechanical resonant filter-fiber

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Silvan Schmid ◽  
Maksymilian Kurek ◽  
Jens Q. Adolphsen ◽  
Anja Boisen
Keyword(s):  
Real Time ◽  
Nanoparticle Detection ◽  
Airborne Nanoparticle

A highly sensitive and selective two-photon fluorescent probe for real-time sensing of cytochrome P450 1A1 in living systems

2018 ◽  
Vol 2 (11) ◽  
pp. 2013-2020 ◽  
Author(s):  
Jing Ning ◽  
Zhenhao Tian ◽  
Bo Wang ◽  
Guangbo Ge ◽  
Yue An ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Real Time ◽  
Fluorescent Probe ◽  
Living Systems ◽  
Cytochrome P450 1A1 ◽  
Two Photon ◽  
Highly Sensitive ◽  
Real Time Tracking ◽  
Cancer Tissues

We designed and developed a highly sensitive and selective two-photon fluorescent probe for real-time tracking CYP1A1 activity in cancer tissues and zebrafish.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Quantitative Measurements on the Ion Etching of TMV

1973 ◽  
Vol 31 ◽  
pp. 336-337
Author(s):  
Irwin Bendet ◽  
Nabil Rizk
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Ion Current ◽  
Beam Diameter ◽  
Ion Etching ◽  
Preliminary Results ◽  
Quantitative Measurements ◽  
Monitoring Devices

Preliminary results reported last year on the ion etching of tobacco mosaic virus indicated that the diameter of the virus decreased more rapidly at 10KV than at 5KV, perhaps reaching a constant value before disappearing completely.In order to follow the effects of ion etching on TMV more quantitatively we have designed and built a second apparatus (Fig. 1), which incorporates monitoring devices for measuring ion current and vacuum as well as accelerating voltage. In addition, the beam diameter has been increased to approximately 1 cm., so that ten electron microscope grids can be exposed to the beam simultaneously.

Fluorescence ratio imaging of dynamic intracellular ionic signals

1988 ◽  
Vol 46 ◽  
pp. 42-43
Author(s):  
R. Y. Tsien ◽  
A. Minta ◽  
M. Poenie ◽  
J.P.Y. Kao ◽  
A. Harootunian
Keyword(s):  
Binding Sites ◽  
Living Cells ◽  
Molecular Engineering ◽  
Ph Indicators ◽  
Highly Sensitive ◽  
Fluorescence Ratio Imaging ◽  
Ratio Imaging ◽  
Technical Advances ◽  
Indicator Dyes ◽  
Fluorescein Dyes

Recent technical advances now enable the continuous imaging of important ionic signals inside individual living cells with micron spatial resolution and subsecond time resolution. This methodology relies on the molecular engineering of indicator dyes whose fluorescence is strong and highly sensitive to ions such as Ca2+, H+, or Na+, or Mg2+. The Ca2+ indicators, exemplified by fura-2 and indo-1, derive their high affinity (Kd near 200 nM) and selectivity for Ca2+ to a versatile tetracarboxylate binding site3 modeled on and isosteric with the well known chelator EGTA. The most commonly used pH indicators are fluorescein dyes (such as BCECF) modified to adjust their pKa's and improve their retention inside cells. Na+ indicators are crown ethers with cavity sizes chosen to select Na+ over K+: Mg2+ indicators use tricarboxylate binding sites truncated from those of the Ca2+ chelators, resulting in a more compact arrangement of carboxylates to suit the smaller ion.

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