Effect of applied magnetic field on remote and noninvasive magnetic nanothermometry

The effects of applied magnetic field on the accuracy of magnetic nanothermometry were investigated through simulation and experiments. The simulation showed that increasing the applied magnetic field improves the accuracy of temperature measurement. In the simulation, a series of first-order Langevin functions was constructed to calculate temperatures within 310 K to 320 K. Experimental results showed that the standard deviations were 1.9 K and 0.28 K in the 5 to 95 and 5 to 410 Oe ranges of applied magnetization field, respectively, in which a real-time magnetization curve recording system under low-frequency (f = 25 Hz) triangle wave was employed to achieve magnetization of superparamagnetic nanoparticles. The experimental results were consistent with those of the simulation. In addition, the mean-square error (MSE) of discretization of the applied magnetic field was discussed to evaluate the results. MSE decreased with the increase in applied magnetic field. Finally, we emphasized the significance of improved temperature probing in hyperthermia and living cells.