## 3 Results
### Temperature and SAR Measurements After Photothermia and Magnetic Hyperthermia Modality  
The photothermal efficiency of the three types of nanomaterials was measured in aqueous suspensions, with iron concentrations ranging from [Fe] = 1 mM to [Fe] = 150 mM. All samples were exposed to an 808 nm laser at a power density of 0.3 W/cm\({}^{2}\) for 5 min (Figure 3A-C). Typical temperature elevation curves, recorded with an IR camera, are shown in Figure 3A for all nanomaterials  
Figure 2: (**A**) The XRD pattern of iron oxide nanoparticles. (**B**) Photographs representing efficient magnetic separation of silica-encapsulated nanoparticle clusters (MNC), whereas silica-encapsulated individual nanoparticles (SPIONs-SIL) are not magnetically responsive. (**C**) The room temperature measurements of the specific magnetization as a function of the magnetic field for the SPIONs (black), silica-encapsulated nanoparticles (SPIONs-SIL) (orange), and MNCs (cyan). (**D**) The change of the \(\zeta\) potentials of the (SPIONs-SIL) (orange) and MNCs (cyan). at an iron concentration of [Fe] = 30 mM, and corresponded to 45.68 \({}^{\circ}\)C for SPIONs-SIL, 43.49 \({}^{\circ}\)C for SPIONs, and 39.51 \({}^{\circ}\)C for MNCs, respectively. This measurement allowed for retrieval of the increase of temperature \(\Delta\)T reached after 5 min, which corresponds to the maximum plateau temperature. The average \(\Delta\)T is shown in Figure 3B for all nanomaterial iron concentrations, and temperature increases were comparable between the SPIONs-SIL and the SPIONs (attaining a max \(\Delta\)T of 20.5 \({}^{\circ}\)C and 20.3 \({}^{\circ}\)C, respectively), while the MNCs attained a max \(\Delta\)T of 17.8 \({}^{\circ}\)C. The maximum temperature that can be reached is attained at high concentrations (in the 20-100 mM range), and further concentration increasing does not translate to a higher heating due to light absorption. This saturation of the heating with higher concentrations resulted in a decrease of the SAR, measured at increasing concentrations (Figure 3C), and converged for all nanoparticles at concentrations above 70 mM of iron. Figure 3: Temperature elevation measurements after (**A**–**C**) photothermia (wavelength of 808 nm, power density of 0.3 W/cm\({}^{2}\)) and (**D**–**F**) magnetic hyperthermia (frequency 470 kHz, field 18 mT). (**A**) Representative temperature increase as a function of time for the suspension at iron concentration [Fe] = 30 mM; (**B**) average temperature increase as function of the iron concentration reached after 5 min of laser exposure; (**C**) average specific absorption rate (SAR) as a function of the iron concentration in different nanomaterials; (**D**) representative temperature increase as a function of time for the suspension at iron concentration [Fe] = 130 mM; (**E**) average temperature increase as a function of the concentration under magnetic hyperthermia; and (**F**) average SAR as a function of the iron concentration in different nanomaterials under magnetic hyperthermia. Similar to photothermala, a series of magnetic hyperthermia measurements were performed when the suspensions of nanomaterials were exposed to an alternating magnetic field (frequency 470 kHz, field 18 mT). Here, temperature elevation curves were recorded at a higher concentration of iron, specifically [Fe] = 130 mM (Figure 3D), and attained temperatures of 42.38 \({}^{\circ}\)C for SPIONs, 41.71 \({}^{\circ}\)C for SPIONs-SIL, and 27.91 \({}^{\circ}\)C for MNCs. Figure 3E shows the average \(\Delta\)T as a function of the iron concentration. These measurements were performed for three decreasing concentrations for SPIONs and SPIONs-SIL (attaining a max \(\Delta\)T of 25 \({}^{\circ}\)C for SPIONs-SIL and 23.6 \({}^{\circ}\)C for SPIONs), and results could not be obtained for MNCs because, for the MNCs, the temperature elevation was not significant enough to be detected at concentrations below 100 mM. For the magnetic hyperthermia modality, the heat generation is linearly proportional to the iron concentration.