Magnetically uniform and tunable Janus particles

Abstract

Magnetic particles serve as an important tool for a variety of biomedical applications but often lack uniformity in their magnetic responsiveness. For quantitative analysis studies, magnetic particles should ideally be monodisperse and possess uniform magnetic properties. Here we fabricate magnetically uniform Janus particles with tunable magnetic properties using a spin-coating and thermal evaporation method. The resulting 2 μm ferromagnetic particles exhibited a 4% magnetic response variability, and the 10 μm ferromagnetic particles exhibited a 1% size variability and an 8% magnetic response variability. Furthermore, by reducing the film thickness, the particle behavior was tuned from ferromagnetic to superparamagnetic.

Asynchronous Magnetic Bead Rotation Microviscometer for Rapid, Sensitive, and Label-Free Studies of Bacterial Growth and Drug Sensitivity

“…$$ln(v_{\text{w}}(T))=0.55908-0.03051T+0.00015T^2,$$ 40 where v w ( T ) is the temperature-dependent viscosity and η ( T ) is the temperature-dependent density of PBS. As shown in Figure 2(b), the viscosity measurements from AMBR agree with expected values that were calculated with Eq.…”

RETRACTED: Using silica molecular sieve modified Fe3O4 particles as supporting matrix for oxygen sensing: Construction, morphology, characterization and sensing performance

“…Some precursive efforts have reported magnetic chemosensors, such as magnetic beads and Janus sensors, which offers a perfect solution for site-specific migration [20][21][22][23][24][25][26][27]. The possibility of combining a magnetic component with oxygen sensors has been confirmed by reports from Kopelman and Klimant and their oxygen sensors based on magnetic particles [28][29][30][31][32][33][34][35][36].…”

Colloidal ribbons and rings from Janus magnetic rods

“…To implement the goal of monodisperse size and homogeneous magnetic response, we take the approach of directionally depositing thin magnetic coatings onto monodisperse colloids [27][28][29]40,41 . To realize shape anisotropy, we first prepare silica rods that are 2.4 ± 0.1 mm long and 0.81 ± 0.04 mm wide (that is, an aspect ratio of 3), using a known method 42 .…”

“…Although some particles of this kind were known from earlier work by others, previous emphasis was on their assembly or dynamics in the presence of external magnetic field [25][26][27][28][29][30][31] . Here, taking advantage of rapid progress in the synthesis of anisotropic colloids [32][33][34][35][36][37] , we go beyond this to delve into the role of shape and constituent anisotropy.…”