2023/07/21 by Sergiu Ruta, Ruta, Sergiu, Yilian Fernández‐Afonso +15
Engineering · Materials Science · Physics and Astronomy · #Applied Physics (physics.app-ph) #Characterization and Applications of Magnetic Nanoparticles #FOS: Physical sciences #Magnetic properties of thin films #Materials Science (cond-mat.mtrl-sci) #Nanoparticle-Based Drug Delivery
paper · pdf · doi:10.48550/arxiv.2307.11521
openalex publication_date 2023/07/21 · openalex created_date 2023/07/25 · openalex updated_date 2026/07/28
Accurate knowledge of the heating performance of magnetic nanoparticles (MNPs) under AC fields is critical for the development of hyperthermia-mediated applications. Usually reported in terms of the specific loss power (SLP) obtained from the temperature variation (ΔT) vs. time (t) curve, such estimate is subjected to a huge uncertainty. Thus, very different SLP values are reported for the same particles when measured on different equipment/laboratories. This lack of control clearly hampers the further development of MNP-mediated heat-triggered technologies. Here we report a device-independent approach to calculate the SLP value of a suspension of MNPs: the SLP is obtained from the analysis of the peak at the field on/off switch of the ΔT(t) curve. The measurement procedure, which itself constitutes a change of paradigm within the field, is based on fundamental physics considerations: specifically to guarantee the applicability of Newton's law of cooling, as i) it corresponds to the ideal scenario in which the temperature profiles of the system during heating and cooling are the same; and ii) it diminishes the role of coexistence of various heat dissipation channels. Such an approach is supported by theoretical and computational calculations to increase the reliability and reproducibility of SLP determination. This is experimentally confirmed, demonstrating a reduction in SLP variation across 3 different devices located in 3 different laboratories. Furthermore, the application of this peak analysis method (PAM) to a rapid succession of field on/off switches that result in a zigzag-like ΔT(t), which we term the zigzag protocol, allows evaluating possible variations of the SLP values with time or temperature.