Analysis of driven nanorod transport through a biopolymer matrix

Mair, Lamar O.; Weinberg, I.; Nacev, Alek; Urdaneta, Mario; Stepanov, P.Yu.; Hilaman, Ryan; Stephanie, Himelfarb,; Superfine, R.

doi:10.1016/j.jmmm.2014.09.059

Cited by 9 publications

(4 citation statements)

References 32 publications

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“…Even at the IONP concentration of 200 mg/L, the number of nanorods present in the fluid was still on the very high side of 4 × 10 8 pts/ μL. Compared to the single nanorod experiment with a magnetophoretic velocity of 4.3 ± 2.9 μm/min, 41 conducted at low nanorod count of 1 × 10 3 pts/μL (particle-to-particle interaction was very minimum along the migration pathway, so no occurrence of cooperative magnetophoresis), the velocity that we observed here was 3000 times faster. Such huge differences indirectly confirmed that the particle we tracked in Figure 7 was undergoing cooperative magnetophoresis, and hence, the particle concentration effect plays an important role for any paper-based magnetophoretic technology development.…”

Section: ■ Experimental Sectionmentioning

confidence: 81%

Low-Gradient Magnetophoresis of Nanospheres and Nanorods through a Single Layer of Paper

Law

Chong

et al. 2023

Langmuir

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The possible magnetophoretic migration of iron oxide nanoparticles through the cellulosic matrix within a single layer of paper is challenging with its underlying mechanism remained unclear. Even with the recent advancements of theoretical understanding on magnetophoresis, mainly driven by cooperative and hydrodynamics phenomena, the contributions of these two mechanisms on possible penetration of magnetic nanoparticles through cellulosic matrix of paper have yet been proven. Here, by using iron oxide nanoparticles (IONPs), both nanospheres and nanorods, we have investigated the migration kinetics of these nanoparticles through grade 4 Whatman filter paper with a particle retention of 20–25 μm. By performing droplet tracking experiments, the real-time stained area growth of the particle droplet on the filter paper, under the influences of a grade N40 NdFeB magnet, were recorded. Our results show that the spatial and temporal expansion of the IONP stain is biased toward the magnet and such an effect is dependent on (i) particle concentration and (ii) particle shape. The kinetics data were first analyzed by treating it as a radial wicking fluid, and later the IONP distribution within the cellulosic matrix was investigated by optical microscopy. The macroscopic flow front velocities of the stained area ranged from 259 μm/s to 16 040 μm/s. Moreover, the microscopic magnetophoretic velocity of nanorod cluster was also successfully measured as ∼214 μm/s. Findings in this work have indirectly revealed the strong influence of cooperative magnetophoresis and the engineering feasibility of paper-based magnetophoretic technology by taking advantage of magnetoshape anisotropy effect of the particles.

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Section: ■ Experimental Sectionmentioning

confidence: 81%

Low-Gradient Magnetophoresis of Nanospheres and Nanorods through a Single Layer of Paper

Law

Chong

et al. 2023

Langmuir

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“…Gold-tipped iron microdevices were synthesized in anodized aluminum oxide (AAO) templates via template guided electrodeposition following established protocols [8]- [10]. Briefly, AAO templates (Whatman Anodisc, nominal pore diameter 0.2 µm) were coated with 0.5 µm silver via thermal evaporation, forming a working electrode.…”

Section: A Magnetic Microdevicesmentioning

confidence: 99%

Magnetic Microdevices for MRI-Based Detection of SARS-CoV-2 Viruses

Mair¹,

Hale²,

Jafari

et al. 2020

IEEE Open J. Eng. Med. Biol.

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To develop a micron-scale device that can operate as an MRI-based reporter for the presence of SARS-CoV-2 virus. Methods: Iron rod microdevices were constructed via template-guided synthesis and suspended in phosphate buffered saline (PBS). Heat-inactivated SARS-CoV-2 viruses were added to the samples and imaged with low-field MRI. Results: MRI of microdevices and viruses showed decreased signal intensity at low concentrations of viruses that recovered at higher concentrations. Electron micrographs suggest that reduced MRI intensity may be due to concentration-dependent shielding of water protons from local magnetic inhomogeneities caused by the iron microdevices. Conclusions: The preliminary results presented in this letter provide justification for further studies exploring the potential diagnostic role of magnetic microdevices in assessing the presence and concentration of SARS-CoV-2 viruses.

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“…4,5 Transport of particles in living tissue is governed by particle size, surface chemistry, 6 and the biological barriers. For capture applications, large particles have disadvantages in the complex biopolymer network comprising tissue arising from their size, 7 including potential exclusion or reduced extraction efficiencies due to entanglements/drag forces. Suspensions of individual superparamagnetic nanoparticles (MNPs) have possible advantages for this application.…”

Section: ■ Introductionmentioning

confidence: 99%

Surface Potential Modulation in Boronate-Functionalized Magnetic Nanoparticles Reveals Binding Interactions: Toward Magnetophoretic Capture/Quantitation of Sugars from Extracellular Matrix

Lyons,

Baile Pomares,

Vidal

et al. 2023

Langmuir

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Phenylboronic acids (BAs) are important synthetic receptors that bind reversibly to cis-diols enabling their use in molecular sensing. When conjugated to magnetic iron oxide nanoparticles, BAs have potential for application in separations and enrichment. Realizing this will require a new understanding of their inherent binding modes and measurement of their binding capacity and their stability in/extractability from complex environments. In this work, 3-aminophenylboronic acid was functionalized to superparamagnetic iron oxide nanoparticles (MNPs, core diameter 8.9 nm) to provide stable aqueous suspensions of functionalized particles (BA-MNPs). The progress of sugar binding and its impact on BA-MNP colloidal stability were monitored through the pH-dependence of hydrodynamic size and zeta potential during incubation with a range of saccharides. This provided the first direct observation of boronate ionization pK a in grafted BA, which in the absence of sugar shifted to a slightly more basic pH than free BA. On exposure to sugar solutions under MNP-limiting conditions, pK a moved progressively to lower pH as maximum capacity was gradually attained. The pK a shift is shown to be greater for sugars with greater BA binding affinity, and on-particle sugar exchange effects were inferred. Colloidal dispersion of BA-MNPs after binding was shown for all sugars at all pHs studied, which enabled facile magnetic extraction of glucose from agarose and cultured extracellular matrix expanded in serum-free media. Bound glucose, quantified following magnetophoretic capture, was found to be proportional to the solution glucose content under glucose-limiting conditions expected for the application. The implications for the development of MNP-immobilized ligands for selective magnetic biomarker capture and quantitation from the extracellular environment are discussed.

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Analysis of driven nanorod transport through a biopolymer matrix

Cited by 9 publications

References 32 publications

Low-Gradient Magnetophoresis of Nanospheres and Nanorods through a Single Layer of Paper

Low-Gradient Magnetophoresis of Nanospheres and Nanorods through a Single Layer of Paper

Magnetic Microdevices for MRI-Based Detection of SARS-CoV-2 Viruses

Surface Potential Modulation in Boronate-Functionalized Magnetic Nanoparticles Reveals Binding Interactions: Toward Magnetophoretic Capture/Quantitation of Sugars from Extracellular Matrix

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