Integrated microHall magnetometer to measure the magnetic properties of nanoparticles

Abstract

Magnetic nanoparticles (MNPs) are widely used in biomedical and clinical applications, including medical imaging, therapeutics, and biological sample processing. Rapid characterization of MNPs, notably their magnetic moments, should facilitate optimization of particle synthesis and accelerate assay development. Here, we report a compact and low-cost magnetometer for fast, on-site MNP characterization. Termed integrated microHall magnetometer (iHM), our device was fabricated using standard semiconductor processes: an array of Hall sensors, transistor switches, and amplifiers were integrated into a single chip, thus improving detection sensitivity and facilitating chip operation. By applying the iHM, we demonstrate versatile magnetic assays. We measured magnetic susceptibility and moments of MNPs using small sample amounts (~10 pL), identified different MNP compositions in mixtures, and detected MNP-labeled single cells.

Microfluidic Synthesis, Control, and Sensing of Magnetic Nanoparticles: A Review

“…However, Hall sensors are used in other magnetometer chips too. In another work, researchers have reported another magnetometer based on the Hall-effect for characterizing magnetic nanoparticles [ 154 ]. The proposed chip consists of Hall sensors, transistor switches, and amplifiers.…”

A novel magnetophoretic-based device for magnetometry and separation of single magnetic particles and magnetized cells

“…The magnetic susceptibility of single magnetic particles is a fundamental parameter indicating their responsiveness to the external magnetic field and their performance in assays. This parameter in previous studies has been measured using tools such as micro-Hall sensors, 21,22 superconducting quantum interference devices (SQUIDs), 23,24 vibrating sample magnetometry (VSM), 25 and magnetophoretic mobility-based measurement. 24,26,27 In some of these tools, an ensemble of magnetic particles, as opposed to single particles, is needed, and an average-based bulk measurement is performed.…”

Chrysoeriol alleviated inflammation in infantile pneumonia by inhibiting PI3K/AKT/mTOR signaling pathway

“…In addition, chrysoeriol ameliorates TPA-induced skin inflammation in mice by inhibiting NF-κB and STAT3 pathways [9]. In lipopolysaccharide (LPS)-induced mouse macrophages, chrysoeriol significantly inhibited PGE2 secretion and COX-2 expression, as well as Akt and P38 phosphorylation, but had no significant effect on ERK phosphorylation [10]. Studies on the therapeutic effect and mechanism of chrysoeriol in children with pneumonia have not been reported.…”