Magnetic nanoparticles and magnetic particle spectroscopy-based bioassays: a 15 year recap

Abstract

Magnetic nanoparticles (MNPs) have unique physical and chemical properties, such as high surface area to volume ratio and size-related magnetism, which are completely different from their bulk materials. Benefiting from the facile synthesis and chemical modification strategies, MNPs have been widely studied for applications in nanomedicine. Herein, we firstly summarized the designs of MNPs from the perspectives of materials and physicochemical properties tailored for biomedical applications. Magnetic particle spectroscopy (MPS), first reported in 2006, has flourished as an independent platform for many biological and biomedical applications. It has been extensively reported as a versatile platform for a variety of bioassays along with the artificially designed MNPs, where the MNPs serve as magnetic nanoprobes to specifically probe target analytes from fluid samples. In this review, the mechanisms and theories of different MPS platforms realizing volumetric- and surface-based bioassays are discussed. Some representative works of MPS platforms for applications such as disease diagnosis, food safety and plant pathology monitoring, drug screening, thrombus maturity assessments are reviewed. At the end of this review, we commented on the rapid growth and booming of MPS-based bioassays in its first 15 years. We also prospected opportunities and challenges that portable MPS devices face in the rapidly growing demand for fast, inexpensive, and easy-to-use biometric techniques.

Nanomaterial-Based Biosensors for SARS-CoV-2 and Future Epidemics

“…MPS works on the principle of measuring the magnetization response of MNPs under the influence of AC excitation fields. 206 Upon the application of an excitation field, MNPs undergo the Neél and Brownian relaxation processes 63,207,208 to align their magnetic moments with the applied field direction. This relaxation occurs because of either the physical rotation of the MNP, as in the case of the Brownian relaxation mechanism, or via rotation of magnetic moment inside the crystalline structure of MNP such as in the case of Neél relaxation.…”

“…MPS-based bioassay approaches have recently gained prominence due to their ease of use, short assay times, low-cost operation, and relative nonrequirement of technical expertise to operate. MPS works on the principle of measuring the magnetization response of MNPs under the influence of AC excitation fields . Upon the application of an excitation field, MNPs undergo the Néel and Brownian relaxation processes ,, to align their magnetic moments with the applied field direction.…”

Multifunctional effects in magnetic nanoparticles for precision medicine: combining magnetic particle thermometry and hyperthermia

“…[1][2][3] In particular, magnetic nanoparticles are currently used as pointlike heat sources in magnetic hyperthermia, sensing elements in magnetic particle imaging (MPI) and/or magnetic particle spectroscopy (MPS), magnetically driveable nanocarriers for active drug targeting. [4][5][6][7][8] In magnetic hyperthermia assisted tumor therapy, the nanoparticles are excited at a sufficiently high frequency as to generate a large amount of magnetic power which is uniformly and locally transferred as heat to a diseased tissue in order either to directly destroy malignant cells 9,10 or to enhance the efficacy of chemo-or radiotherapy practice by suitably increasing the temperature of the target. [11][12][13] Therapeutic (in vivo) applications of magnetic hyperthermia have to be tailored to a patient's needs and therefore require measuring as accurately as possible the actual temperature of the target in a noninvasive way, i.e., without recurring to surgery.…”

“…1–3 In particular, magnetic nanoparticles are currently used as pointlike heat sources in magnetic hyperthermia, sensing elements in magnetic particle imaging (MPI) and/or magnetic particle spectroscopy (MPS), magnetically driveable nanocarriers for active drug targeting. 4–8…”

Static and Dynamic Magnetization Responses of Self-Assembled Magnetic Nanoparticle Chains

“…This information will assist us in analyzing how the relative orientation of effective anisotropy in an MNP with respect to the alternating magnetic field guides the total energies and torques as well as their effects on the observed variations in dynamic magnetization responses. In addition, since both MPS and MPI are popular biosensing and medical imaging platforms, ,,– the harmonics of MNPs with different easy axis orientations relative to the external fields can help researchers with designing self-assembled chains for better application performance.…”