Magnetic Particle Spectroscopy: A Short Review of Applications Using Magnetic Nanoparticles

Abstract

Magnetic particle spectroscopy (MPS), also called magnetization response spectroscopy, is a novel measurement tool derived from magnetic particle imaging (MPI). It can be interpreted as a zero-dimensional version of MPI scanner. MPS was primarily designed for characterizing superparamagnetic iron oxide nanoparticles (SPIONs) regarding their applicability for MPI. In recent years, it has evolved into an independent, versatile, highly sensitive, inexpensive platform for biological and biomedical assays, cell labeling and tracking, and blood analysis. MPS has also developed into an auxiliary tool for magnetic imaging and hyperthermia by providing high spatial and temporal mappings of temperature and viscosity. Furthermore, other MPS-based applications are being explored such as magnetic fingerprints for product tracking and identification in supply chains. There are a variety of novel MPS-based applications being reported and demonstrated by many groups. In this short review, we highlighted some of the representative applications based on MPS platform, thereby providing a roadmap of this technology and our insights for researchers in this area.

Superparamagnetic Iron Oxide Nanoparticles and Essential Oils: A New Tool for Biological Applications

“…The method of Matrix-Assisted Pulsed Laser Evaporation (MAPLE) was used to produce the bioactive film containing magnetite nanoparticles and the Melissa essential oil that was mainly constituted by 28% limonene, 31% β-citronellal, 15% β-citral, 9% α-citral, and 8% caryophyllene. In this experiment, the biological activity extends over a longer period of time than that previously reported [ 124 ], leading these authors to suggest replacing the coated wound dressing every day.…”

“…Magnetic particle imaging (MPI) measures and maps the concentration of SPIONs over a spatial position. In magnetic particle spectroscopy (MPS), sinusoidal magnetic fields are applied to periodically magnetize SPIONs; then, the dynamic magnetic responses of SPIONs, which contain unique higher odd harmonics, are harvested by a pair of pick-up coils [ 124 ]. These harmonics are useful metrics for characterizing the magnetic nanoparticle ferrofluids.…”

“…The method was also rapid (results provided in 10 s), needing only non-technicians with minimum technical training. This method shows some importance to be improved for several reasons; for example, according to the World Health Organization (WHO), influenza viruses, responsible for seasonal epidemics of acute respiratory illness known as influenza or flu, are responsible for 250,000 to 500,000 deaths annually [ 124 ]. In this review article, the authors consider that this approach must be explored for the detection of SARS-CoV-2, since current diagnostic tests are based on real-time reverse transcription-polymerase chain reaction (RT-PCR) that requires 48 h for having a result, expensive equipment, and trained technicians, and there have been many global deaths.…”

Magnetic-Nanosensor-Based Virus and Pathogen Detection Strategies before and during COVID-19

“… 93 , 94 Herein, in MPS-based immunoassays, the nonlinear magnetic responses of MNPs along with their rotational degree of freedom are used as metrics for different biosensing purposes. 44 In a MPS platform, external sinusoidal magnetic fields (also called excitation fields) are applied to periodically magnetize (and magnetically saturate) the MNPs, as shown in Figure 5 A1,A3. 85 − 87 , 95 − 101 The time-varying dipolar magnetic fields generated by MNPs as a response to the applied fields ( Figure 5 A2,A4) are monitored by pick-up coils.…”

Uncovering the Magnetic Particle Imaging and Magnetic Resonance Imaging Features of Iron Oxide Nanocube Clusters

“…This combined diagnostic and therapeutic approach is doable because the way MNPs are excited in MPI is similar to that in MH, where alternating magnetic fields are used. However, the range of frequency required for MPI differs from that of MH ( f ≤ 35 kHz versus f ≥ 110 kHz, respectively) [ 17 ]. Despite the use of a clinically approved MRI contrast agent, Resovist ® , as a common standard, the low heat performance of Resovist ® and the current availability of a wide portfolio of MNPs, has pushed early research towards the exploitation of optimal MNPs with combined MPI, MRI, and MH properties [ 18 ].…”