Magnetic Sensing Potential of Fe₃O₄ Nanocubes Exceeds That of Fe₃O₄ Nanospheres

Abstract

This paper highlights the relation between the shape of iron oxide (Fe3O4) particles and their magnetic sensing ability. We synthesized Fe3O4 nanocubes and nanospheres having tunable sizes via solvothermal and thermal decomposition synthesis reactions, respectively, to obtain samples in which the volumes and body diagonals/diameters were equivalent. Vibrating sample magnetometry (VSM) data showed that the saturation magnetization (Ms) and coercivity of 100–225 nm cubic magnetic nanoparticles (MNPs) were, respectively, 1.4–3.0 and 1.1–8.4 times those of spherical MNPs on a same-volume and same-body diagonal/diameter basis. The Curie temperature for the cubic Fe3O4 MNPs for each size was also higher than that of the corresponding spherical MNPs; furthermore, the cubic Fe3O4 MNPs were more crystalline than the corresponding spherical MNPs. For applications relying on both higher contact area and enhanced magnetic properties, higher-Ms Fe3O4 nanocubes offer distinct advantages over Fe3O4 nanospheres of the same-volume or same-body diagonal/diameter. We evaluated the sensing potential of our synthesized MNPs using giant magnetoresistive (GMR) sensing and force-induced remnant magnetization spectroscopy (FIRMS). Preliminary data obtained by GMR sensing confirmed that the nanocubes exhibited a distinct sensitivity advantage over the nanospheres. Similarly, FIRMS data showed that when subjected to the same force at the same initial concentration, a greater number of nanocubes remained bound to the sensor surface because of higher surface contact area. Because greater binding and higher Ms translate to stronger signal and better analytical sensitivity, nanocubes are an attractive alternative to nanospheres in sensing applications.

<p>Multi-Stimuli-Responsive DOX Released from Magnetosome for Tumor Synergistic Theranostics</p>

“…Kolhatkar et al also explained that greater crystallization in the multi-domain size regime of truncated octahedral Fe 3 O 4 nanoparticles resulted in stronger binding to substrate surfaces and better magnetic properties. 20 The diagonal length of IONPs was found to be 15.6±3.8 nm ( Figure S4A ), and the X-ray diffraction (XRD) pattern confirmed the crystallization of Fe 3 O 4 according to JCPDS card no. 19–0629 ( Figure S4B ), while high-resolution TEM images explained the truncated octahedral morphology of IONPs ( Figure S4C ).…”

“… 19 The advantages of using truncated octahedral Fe 3 O 4 nanoparticles (IONPs) over spherical ones include (1) higher saturation magnetization (Ms), higher Curie temperature, greater crystallization, greater contact area, enhanced magnetic properties, stronger signals and better analytical sensitivity. 20 …”

Copper Immobilized on Isonicotinic Acid Hydrazide Functionalized Nano‐Magnetite as a Novel Recyclable Catalyst for Direct Synthesis of Phenols and Anilines

“…The size range of Fe 3 O 4 @INH@Cu nanoparticle was determined by the transmission electron microscopy (TEM) images (Figure ). The multidomain size range spherical (body diagonals of 100, 75, and 50 nm) Fe 3 O 4 @INH@Cu was shown in Figure S7 in the Supporting Information . The images reveal that the Fe 3 O 4 @INH@Cu nanoparticles are spherical.…”

Magnetic Iron Nanocubes Effectively Capture Epithelial and Mesenchymal Cancer Cells

“…Additionally, nanocubes exhibit high surface area, excellent binding capacity, and higher analytical sensitivity as compared to traditional spherical nanoparticles. 34 …”