Coplanar waveguide method for microwave and ferromagnetic resonance characterization of nanocarbon powders decorated with magnetic nanoparticles

2017 ◽  
Vol 59 (9) ◽  
pp. 2330-2335 ◽  
Author(s):  
Francisco Mederos-Henry ◽  
Sophie Hermans ◽  
Isabelle Huynen
Keyword(s):  
Magnetic Nanoparticles ◽  
Ferromagnetic Resonance ◽  
Coplanar Waveguide ◽  
Waveguide Method

Ferromagnetic Resonance Biosensor for Homogeneous and Volumetric Detection of DNA

2017 ◽  
Author(s):  
Bo Tian ◽  
Peter Svedlindh ◽  
Mattias Strömberg ◽  
Erik Wetterskog
Keyword(s):  
Magnetic Nanoparticles ◽  
Ferromagnetic Resonance ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Rolling Circle Amplification ◽  
Resonance Field ◽  
Isothermal Amplification ◽  
Detection Sensitivity ◽  
Serum Samples ◽  
Rolling Circle

In this work, we demonstrate for the first time, a ferromagnetic resonance (FMR) based homogeneous and volumetric biosensor for magnetic label detection. Two different isothermal amplification methods, <i>i.e.</i>, rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) are adopted and combined with a standard electron paramagnetic resonance (EPR) spectrometer for FMR biosensing. For RCA-based FMR biosensor, binding of RCA products of a synthetic Vibrio cholerae target DNA sequence gives rise to the formation of aggregates of magnetic nanoparticles. Immobilization of nanoparticles within the aggregates leads to a decrease of the net anisotropy of the system and a concomitant increase of the resonance field. A limit of detection of 1 pM is obtained with an average coefficient of variation of 0.16%, which is superior to the performance of other reported RCA-based magnetic biosensors. For LAMP-based sensing, a synthetic Zika virus target oligonucleotide is amplified and detected in 20% serum samples. Immobilization of magnetic nanoparticles is induced by their co-precipitation with Mg<sub>2</sub>P<sub>2</sub>O<sub>7</sub> (a by-product of LAMP) and provides a detection sensitivity of 100 aM. The fast measurement, high sensitivity and miniaturization potential of the proposed FMR biosensing technology makes it a promising candidate for designing future point-of-care devices.<br>

scholarly journals Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1757
Author(s):  
Yesica Vicente-Martínez ◽  
Manuel Caravaca ◽  
Antonio Soto-Meca ◽  
Miguel Ángel Martín-Pereira ◽  
María del Carmen García-Onsurbe
Keyword(s):  
Magnetic Nanoparticles ◽  
Nitrate Content ◽  
Adsorption Efficiency ◽  
Experimental Conditions ◽  
Dependent Behavior ◽  
Before And After ◽  
Naoh Solution ◽  
High Concentrations ◽  
Interference Studies

This paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe3O4@AgNPs) were synthesized and used as an adsorbent of nitrates. Experimental conditions, including the pH, adsorbent and adsorbate dose, temperature and contact time, were analyzed to obtain the highest adsorption efficiency for different concentration of nitrates in water. A maximum removal efficiency of 100% was reached for 2, 5, 10 and 50 mg/L of nitrate at pH = 5, room temperature, and 50, 100, 250 and 500 µL of Fe3O4@AgNPs, respectively. The characterization of the adsorbent, before and after adsorption, was performed by energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. Nitrates can be desorbed, and the adsorbent can be reused using 500 µL of NaOH solution 0.01 M, remaining unchanged for the first three cycles, and exhibiting 90% adsorption efficiency after three regenerations. A deep study on equilibrium isotherms reveals a pH-dependent behavior, characterized by Langmuir and Freundlich models at pH = 5 and pH = 1, respectively. Thermodynamic studies were consistent with physicochemical adsorption for all experiments but showed a change from endothermic to exothermic behavior as the temperature increases. Interference studies of other ions commonly present in water were carried out, enabling this procedure as very selective for nitrate ions. In addition, the method was applied to real samples of seawater, showing its ability to eliminate the total nitrate content in eutrophized waters.

scholarly journals Production and characterization of chitooligosaccharides by the fungal chitinase Chit42 immobilized on magnetic nanoparticles and chitosan beads: selectivity, specificity and improved operational utility

RSC Advances ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 5529-5536
Author(s):  
Peter E. Kidibule ◽  
Jessica Costa ◽  
Andrea Atrei ◽  
Francisco J. Plou ◽  
Maria Fernandez-Lobato ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Industrial Application ◽  
Chitosan Beads

Chitin-active enzymes are of great biotechnological interest due to the wide industrial application of chitinolytic materials.

Curcuminoids-conjugatiked multicore magnetic nanoparticles: design and characterization of a potential theranostic nanoplatform

2021 ◽  
pp. 160448
Author(s):  
Evelyn C.S. Santos ◽  
Jamili A. Cunha ◽  
Marcel G. Martins ◽  
Bianca M. Galeano-Villar ◽  
Richard J. Caraballo-Vivas ◽  
...  
Keyword(s):  
Magnetic Nanoparticles

scholarly journals RF Small and large signal characterization of a 3D integrated GaN/RF-SOI SPST switch

2021 ◽  
pp. 1-6
Author(s):  
Frédéric Drillet ◽  
Jérôme Loraine ◽  
Hassan Saleh ◽  
Imene Lahbib ◽  
Brice Grandchamp ◽  
...  
Keyword(s):  
Power Level ◽  
Coplanar Waveguide ◽  
Average Power ◽  
Input Power ◽  
Capacitive Coupling ◽  
Rf Switch ◽  
Large Signal ◽  
Waveguide Transmission ◽  
Signal Characterization

Abstract This paper presents the radio frequency (RF) measurements of an SPST switch realized in gallium nitride (GaN)/RF-SOI technology compared to its GaN/silicon (Si) equivalent. The samples are built with an innovative 3D heterogeneous integration technique. The RF switch transistors are GaN-based and the substrate is RF-SOI. The insertion loss obtained is below 0.4 dB up to 30 GHz while being 1 dB lower than its GaN/Si equivalent. This difference comes from the vertical capacitive coupling reduction of the transistor to the substrate. This reduction is estimated to 59% based on a RC network model fitted to S-parameters measurements. In large signal, the linearity study of the substrate through coplanar waveguide transmission line characterization shows the reduction of the average power level of H2 and H3 of 30 dB up to 38 dBm of input power. The large signal characterization of the SPST shows no compression up to 38 dBm and the H2 and H3 rejection levels at 38 dBm are respectively, 68 and 75 dBc.

Characterization of as-synthesized FeCo magnetic nanoparticles by coprecipitation method

2013 ◽  
Vol 113 (17) ◽  
pp. 17A313 ◽  
Author(s):  
Jinu Kim ◽  
Jinbae Kim ◽  
Jongryoul Kim ◽  
Ki Hyeon Kim
Keyword(s):  
Magnetic Nanoparticles ◽  
Coprecipitation Method
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