scholarly journals Field-dependent dynamic responses from dilute magnetic nanoparticle dispersions

Nanoscale ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 2052-2066 ◽  
Author(s):  
Jeppe Fock ◽  
Christoph Balceris ◽  
Rocio Costo ◽  
Lunjie Zeng ◽  
Frank Ludwig ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Ac Susceptibility ◽  
Bivariate Distribution ◽  
Dynamic Responses ◽  
Nanoparticle Dispersions ◽  
Field Dependent

AC susceptibility (ACS) and optomagnetic (OM) measurements vs. field and frequency allow determination of the bivariate distribution in moment and size. The obtained correlation provides information on the morphology of the magnetic nanoparticles.

PINNING ENERGY AND VORTEX-PHASE DIAGRAM OF MgB2 BULK MATERIALS

2003 ◽  
Vol 17 (04n06) ◽  
pp. 584-589 ◽  
Author(s):  
G. GHIGO ◽  
D. BOTTA ◽  
A. CHIODONI ◽  
R. GERBALDO ◽  
L. GOZZELINO ◽  
...  
Keyword(s):  
Ac Susceptibility ◽  
Bulk Materials ◽  
Creep Properties ◽  
Pinning Energy ◽  
Vortex Phase Diagram ◽  
Vortex Phase ◽  
A Value ◽  
Independent Analysis ◽  
Field Dependent

By using ac susceptibility measurements at different frequencies and dc fields we investigated the creep properties of MgB 2 bulk samples. Two independent analysis have been used in order to determine the behavior of the pinning energy in the whole investigated temperature and field ranges. The main result of the first analysis (χ′′-peak analysis) is that the attempt frequency v 0 in the Arrhenius formula is about 104 Hz , a value significantly lower than that usually reported for HTS's. By means of the second analysis a field dependent maximum of the pinning energy as a function of temperature has been found. It turns out that the phase points corresponding to the peak of the pinning energy are coincident with the irreversibility line, as determined by magnetization cycles. The results coming from different and independent analysis lead to the determination of a vortexphase diagram for bulk MgB 2, which seems to be largely dominated by creep phenomena.

scholarly journals Simultaneous Determination of Penicillin G and Chloramphenicol in Milk by a Magnetic Nanoparticle-Based Fluorescent Immunoassay

2020 ◽  
Vol 14 (1) ◽  
pp. 59-69
Author(s):  
Milka Atanasova ◽  
Yavor Ivanov ◽  
Elena Zvereva ◽  
Anatoly Zherdev ◽  
Tzonka Godjevargova
Keyword(s):  
Magnetic Nanoparticles ◽  
Simultaneous Determination ◽  
Magnetic Nanoparticle ◽  
Limit Of Detection ◽  
Animal Health ◽  
Simultaneous Detection ◽  
Penicillin G ◽  
Frequent Use ◽  
Simultaneous Immunoassay

Background: Antibiotic residues are a problem of increasing importance and have direct consequences for human and animal health. The frequent use of antibiotics in veterinary practice causes their excretion in milk in dairy cattle. This way, they can easily enter the human body through the consumption of milk and dairy products. Objectives: This induces the need for accurate and sensitive methods to monitor antibiotic levels in milk. The aim of this study was to develop a rapid and sensitive magnetic nanoparticle-based fluorescence immunoassay for the simultaneous detection of chloramphenicol and penicillin G in milk. Methods: Magnetic nanoparticles were synthesized and functionalized with (3-aminopropyl)triethoxysilane. Chloramphenicol-Ovalbumin and Chloramphenicol-Ovalbumin-Fluorescein-5-isothiocyanate conjugates were prepared. Penicillin G – ATTO 633 fluorescent conjugate was synthesized. Antibodies against chloramphenicol and penicillin G were immobilized onto the magnetic nanoparticles. The competitive fluorescent immunoassay was developed. The optimal concentration of the antibody-magnetic nanoparticles and the fluorescent conjugates for the assay was determined. The calibration curves for the antibiotics in buffer and milk were plotted. Fluorescent immunoassay for the simultaneous determination of chloramphenicol and penicillin G in milk was developed. Results: The limit of detection by the simultaneous immunoassay of chloramphenicol and penicillin G in milk was 0.85 ng/mL and 1.6 ng/mL, respectively. The recovery of different concentrations of chloramphenicol and penicillin G in milk samples varied from 98% to 106%. Conclusions: A rapid and sensitive magnetic nanoparticle-based immunofluorescent assay for the simultaneous determination of chloramphenicol and penicillin G in milk was developed. The magnetic nanoparticles ensured rapid and easy procedure.

scholarly journals In-situ investigation of temperature induced agglomeration in non-polar magnetic nanoparticle dispersions by small angle X-ray scattering

Nanoscale ◽  
2021 ◽  
Author(s):  
Christian Appel ◽  
Björn Kuttich ◽  
Tobias Kraus ◽  
Bernd Stühn
Keyword(s):  
Magnetic Nanoparticles ◽  
Small Angle ◽  
Magnetic Nanoparticle ◽  
Length Scale ◽  
X Ray ◽  
X Ray Scattering ◽  
Nanoparticle Dispersions ◽  
In Situ Investigation ◽  
Ray Scattering

Non-polar magnetic nanoparticles exhibit agglomeration upon cooling. This process is followed by in-situ small angle X-ray scattering to assess structural properties of the emerging agglomerates. On the length scale of...

scholarly journals A Perspective on Modelling Metallic Magnetic Nanoparticles in Biomedicine: From Monometals to Nanoalloys and Ligand-Protected Particles

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3611
Author(s):  
Barbara Farkaš ◽  
Nora H. de de Leeuw
Keyword(s):  
Magnetic Nanoparticles ◽  
Biomedical Applications ◽  
Magnetic Nanoparticle ◽  
Cobalt Nanoparticles ◽  
Magnetic Behaviour ◽  
Resonance Imaging ◽  
Magnetic Nanoparticle Hyperthermia ◽  
Magnetic Resonance Imaging Mri ◽  
Simulation Systems

The focus of this review is on the physical and magnetic properties that are related to the efficiency of monometallic magnetic nanoparticles used in biomedical applications, such as magnetic resonance imaging (MRI) or magnetic nanoparticle hyperthermia, and how to model these by theoretical methods, where the discussion is based on the example of cobalt nanoparticles. Different simulation systems (cluster, extended slab, and nanoparticle models) are critically appraised for their efficacy in the determination of reactivity, magnetic behaviour, and ligand-induced modifications of relevant properties. Simulations of the effects of nanoscale alloying with other metallic phases are also briefly reviewed.

MAGNETIC NANOPARTICLE BASED FLUORESCENCE IMMUNOASSAY FOR DETERMINATION OF OCHRATOXIN A

2020 ◽  
pp. 403-405
Author(s):  
Z. Becheva ◽  
M. Atanasova
Keyword(s):  
Magnetic Nanoparticles ◽  
Ochratoxin A ◽  
Polyclonal Antibody ◽  
Magnetic Nanoparticle ◽  
Fluorescein Isothiocyanate ◽  
Fluorescence Immunoassay ◽  
Constant Concentration ◽  
Competitive Immunoassay ◽  
Immunofluorescent Analysis

Ochratoxins are possible human carcinogens. The aim of this study is to develop a sensitive competitive immunofluorescent analysis for determination of ochratoxin A (OTA) on the base of immobilized polyclonal antibody against ochratoxin and F(ab)2 fragment on magnetic nanoparticles (MNPs). Competitive immunoassay was performed by using variety concentrations of OTA and constant concentration of fluorescein isothiocyanate (FITC) labeled OTA. The analytical characteristics of the analysis with immobilized polyclonal antibody and F(ab)2 fragment were very closely.

Determination of Lignocellulase Activity and Gene Expression Using Magnetic Nanoparticle-Based Electrochemical Biosensor

2012 ◽  
Vol 518-523 ◽  
pp. 309-313
Author(s):  
Meng Shi Wu ◽  
Lin Tang ◽  
Guang Ming Zeng ◽  
Xiao Xia Lei ◽  
Zhen Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Electrochemical Biosensor ◽  
Molecular Targets ◽  
Electrochemical Biosensors

Many types of electrochemical biosensors employ magnetic nanoparticles which have been surface functionalized to recognize specific molecular targets. Here the paper emphatically introduced the operation principle of biosensing magnetic nanoparticles, the overall strategy for fabricating magnetic nanoparticles-based biosensor and the latest application progress in detecting lignocellulase activity and gene expression by electrochemical biosensors.

Preparation of Cysteine‐Functionalized Fe 3 O 4 Magnetic Nanoparticles for Determination of Cu 2+

2021 ◽  
Vol 6 (26) ◽  
pp. 6683-6689
Author(s):  
Dan Liu ◽  
Heping Tan ◽  
Lili Meng ◽  
Hailang Jia ◽  
Wenjuan Zhou ◽  
...  
Keyword(s):  
Magnetic Nanoparticles

scholarly journals Understanding intracellular nanoparticle trafficking fates through spatiotemporally resolved magnetic nanoparticle recovery

2021 ◽  
Author(s):  
Emily Sheridan ◽  
Silvia Vercellino ◽  
Lorenzo Cursi ◽  
Laurent Adumeau ◽  
James A. Behan ◽  
...  
Keyword(s):  
Decision Making ◽  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Magnetic Extraction

We describe how magnetic nanoparticles can be used to study intracellular nanoparticle trafficking, and how magnetic extraction may be integrated with downstream analyses to investigate nanoscale decision-making events.

Sign in / Sign up

Export Citation Format

Share Document