Flexible Chains of Ferromagnetic Nanoparticles

Townsend, James; Burtovyy, Ruslan; Galabura, Yuriy; Luzinov, Igor

doi:10.1021/nn501787v

Cited by 28 publications

(24 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous reports showed that magnetic induction [4] and external coating by induced self-assembly [5] are two effective methods for forming magnetic nanochains with nanoparticles. For microscopic systems, the size of the magnetic stirrer must be within nanoscale.…”

mentioning

confidence: 99%

Nanoscale Magnetic Stirring Bars for Heterogeneous Catalysis in Microscopic Systems

et al. 2015

View full text Add to dashboard Cite

Nanometer-sized magnetic stirring bars containing Pd nanoparticles (denoted as Fe3 O4 -NC-PZS-Pd) for heterogeneous catalysis in microscopic system were prepared through a facile two-step process. In the hydrogenation of styrene, Fe3 O4 -NC-PZS-Pd showed an activity similar to that of the commercial Pd/C catalyst, but much better stability. In microscopic catalytic systems, Fe3 O4 -NC-PZS-Pd can effectively stir the reaction solution within microdrops to accelerate mass transfer, and displays far better catalytic activity than the commercial Pd/C for the hydrogenation of methylene blue in an array of microdroplets. These results suggested that the Fe3 O4 -NC-PZS-Pd could be used as nanoscale stirring bars in nanoreactors.

show abstract

mentioning

confidence: 99%

Nanoscale Magnetic Stirring Bars for Heterogeneous Catalysis in Microscopic Systems

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Theoretical analysis and experiments revealed that the field-induced aggregation process of dipolar particles is a complex phenomenon and the structure of aggregates depends on the balance of magnetic forces, thermal fluctuations and other interaction mechanisms between NPs. NPs in the aggregates may undergo rearrangements [21][22][23][24] . The dynamics of the aggregates facilitates an increased efficiency of biocatalytic reactions in the nanocompartments generated in the aggregates.…”

Section: Nature Catalysismentioning

confidence: 99%

Magnetic field remotely controlled selective biocatalysis

et al. 2017

View full text Add to dashboard Cite

M aterials that efficiently release biological molecules or therapeutic chemicals on demand using exposure to remotely controlled and safe external sources of energy, such as magnetic fields, could find applications for drug delivery 1 , biotechnology 2,3 and biosensors 4 . Because live tissue and synthetic polymers are not responsive to weak magnetic fields, the development of magnetic-field-responsive soft materials has been reported by combining magnetic nanoparticles and stimuli-responsive soft materials 5 . Magnetic nanoparticles interact with magnetic fields and transduce magnetic field energy into physical or chemical changes in the soft material. Materials that control enzymatic processes are one example of such soft materials. Enzymes are extensively used to change or degrade colloidal particles, capsules, and their assemblies to trigger release of the cargo via biocatalytic reactions 6,7 .In all eukaryotes, metabolic pathways are precisely organized and regulated. This precise control is based in part on the high selectivity of biocatalytic reactions and controlled transport of chemicals and biomacromolecules across membranes that compartmentalize cells, organelles and organs. Highly selective biocatalysis alone cannot orchestrate complex systems of biochemical reactions without the supporting role of signal-triggered synthesis, release, secretion, conversion and degrading processes that take place in different compartments in cells and organs. Despite being highly selective, enzymes cannot provide 100% selectivity. In particular, enzymes could interact with a number of substrates of a similar chemical structure (for example, proteases are highly promiscuous catalysts), be degraded by other enzymes or even by self-digestion upon secretion into a complex biological environment, or undergo undesired aggregation, crystallization or nonspecific adsorption, which would strongly damage the efficiency of the biocatalytic process. However, the overall high specificity of biocatalytic processes is strengthened by localizing the enzymatic reactions within a specific environment and spatial compartments.Inspired by this hierarchical design in live systems, diverse stimuli-responsive functional materials have been reported, involving various architectures that respond to changes in magnetic fields [8][9][10] . However, it remains challenging to create a reactive system that preserves enzyme molecules from destructive environments and undesired interactions while being able to initiate the designated reaction when needed. Different approaches have been developed to preserve enzymes for storage and delivery before activating them on demand in a magnetic field at the targeted location. A number of studies aimed at controlling the kinetics of biocatalytic reactions in model systems [11][12][13][14][15] have explored magnetic-field-triggered changes of the local concentration and mobility of enzymes. However, it is difficult to apply many of such approaches to live tissue because of limitations associated with degradat...

show abstract

“…Several interesting phenomena are known for ferromagnetic filaments -in the AC magnetic field with a frequency high enough they orient perpendicularly to the field [5]. When magnetic field direction is changed, filaments form snake like 'S' shape [6]. If the direction is inverted, ferromagnetic filament makes a loop [7], which further relaxes by 3D motion.…”

Section: Introductionmentioning

confidence: 99%

Deformation of flexible ferromagnetic filaments under a rotating magnetic field

Zaben

Kitenbergs

Cēbers

2020

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

A B S T R A C TResearch on magnetic particles dispersed in a fluid medium, actuated by a rotating magnetic field, is becoming increasingly active for both lab-on-chip and bio-sensing applications. In this study, we experimentally investigate the behaviour of ferromagnetic filaments in a rotating field. Filaments are synthesized by linking micron-sized ferromagnetic particles with DNA strands. The experiments were conducted under different magnetic field strengths, frequencies and filament sizes, and deformation of the filaments was registered via microscope and camera. The results obtained showed that the body deformation is larger for longer filaments and higher frequencies and lower for larger magnetic field. The angle between the filament tangent at the centre and the magnetic field direction increases linearly with frequency at low-frequency regime. A further increase in the frequency will result in filament movement out of plane when the angle approaches 90 degrees. The experimental results were used to estimate magnetic moment and the bending elasticity of the filament.

show abstract

Flexible Chains of Ferromagnetic Nanoparticles

Cited by 28 publications

References 67 publications

Nanoscale Magnetic Stirring Bars for Heterogeneous Catalysis in Microscopic Systems

Nanoscale Magnetic Stirring Bars for Heterogeneous Catalysis in Microscopic Systems

Magnetic field remotely controlled selective biocatalysis

Deformation of flexible ferromagnetic filaments under a rotating magnetic field

Contact Info

Product

Resources

About