Real-time magnetic nanothermometry: The use of magnetization of magnetic nanoparticles assessed under low frequency triangle-wave magnetic fields

Abstract

In this study, we propose and demonstrate the usefulness of employing time-varying magnetization of a magnetic nanoparticle (MNP) based sample, induced by low frequency (f = 25 Hz) triangular-wave magnetic field, to achieve the approach of real-time recording of magnetization curve, which allows precise and noninvasive temperature probing with real-time performance. Moreover, the present report introduces the design and performed the test of a detection system for accurate and real-time recording of the magnetization curve of MNP-based samples. We found that by employing the magnetization curve of a magnetic fluid sample containing magnetite nanoparticles of about 30 nm in diameter the accuracy of the temperature probing is about 0.32 K (0.1% relative accuracy), with response time of 1 s. Furthermore, an increase in response time from 1 to 8 s improves the accuracy of temperature probing from 0.32 to 0.20 K. Finally, we envisage that breakthroughs in clinical hyperthermia, targeted drug delivery and basic cell research can be accomplished while using the approach reported in this study.

Study of Magnetic Nanoparticle Spectrum for Magnetic Nanothermometry

“…7) represent the dependence of temperature probing accuracy with respect to the response time. Indeed, we found that the increase in the response time improves the temperature probing accuracy, in good agreement with our recent report [20]. This finding is of great importance to the application of magnetic nanothermometry.…”

“…2) are calculated by the digital phase-sensitive detector (DPSD) algorithm. The MNP magnetization is temperature dependent no matter how complex the particle-particle interaction and the particle size distribution are, and therefore, it has been proved theoretically and experimentally to provide the background for magnetic nanothermometry [16]- [20]. Fig.…”

“…In this paper, pick-up coils are used as magnetic sensors for the MNP magnetization measurement. The output signal of the pick-up coils is induced not only by the MNP time-varying magnetization but also by the applied ac magnetic field, named residual magnetic field [20], [23]. To suppress the signal induced by the residual magnetic field, a pair of pick-up coils is connected to each other in opposite series, as schematically shown in Fig.…”

“…The temperature sensitivity of the MNP magnetization curve as well as the impact of model construction, inverse calculation method, and magnetic field strength was found to achieve highly accurate temperature probing with an accuracy of 0.017 K [19]. Furthermore, a novel system was designed to measure the MNP magnetization curve for real-time magnetic nanothermometry under low-frequency triangular-wave magnetic fields [20].…”

Lock-In Thermography as an Analytical Tool for Magnetic Nanoparticles: Measuring Heating Power and Magnetic Fields

“…It can therefore represent a first step toward real-time and accurate heat quantification in vivo, which is an essential step toward implementation of magnetic hyperthermia in clinic. 36,37 Nowadays, the most commonly used and reliable systems for probing the heat of SPIONs are fiber optic cables, which can record information from the colloidal suspension. However, the results are dependent on the spatial position of the temperature sensor.…”