Assessing the parameters modulating optical losses of iron oxide nanoparticles under near infrared irradiation

Abstract

Heating mediated by iron oxide nanoparticles subjected to near infrared irradiation has recently gained lots of interest. The high optical loss values reported in combination with the optical technologies already...

Quantitative Comparison of the Light-to-Heat Conversion Efficiency in Nanomaterials Suitable for Photothermal Therapy

“…Iron oxide NHs are characterized by good biocompatibility and biodegradability . For these NHs, the heat generation mechanism is not yet well understood . Among the investigated NHs, the γ-Fe 2 O 3 -Au and γ-Fe 2 O 3 belong to this group.…”

“…Similarly, for Ag 2 S, Ag-Ag 2 S dimers, AuNRs, γ-Fe 2 O 3 , and γ-Fe 2 O 3 -Au, no obvious wavelength dependence was observed. Different results were presented on the work on maghemite, which showed wavelength dependence in the range of 700–1280 nm, and the iHCE almost doubled at the longest wavelength; however, these results were obtained for a material with different morphology and size. There are very few publications illustrating iHCE as a function of wavelength, while for materials that show no luminescence and where the impact of scattering on the results is negligible, we expect a constant value of iHCE.…”

“…Diverse iHCEs for iron oxide NHs mentioned in the literature were obtained. Lozano-Pedraza et al presented that for iron oxides with a dominant maghemite phase, the NH size (in the range of 9–18 nm) does not significantly influence the iHCE, but different shapes result in different iHCEs. In contrast, Sadat et al showed a graph presenting the size dependence of different Fe 2 O 3 NHs, where the iHCE decreased with the rise in NH size from ∼80% iHCE for 10 nm NHs covered by PAA to ∼30% for ∼100 nm NHs covered by PS to ∼18% for Fe 2 O 3 beads.…”

“…54 For these NHs, the heat generation mechanism is not yet well understood. 55 Among the investigated NHs, the γ-Fe 2 O 3 -Au and γ-Fe 2 O 3 belong to this group.…”

Core-shell iron oxide@stellate mesoporous silica for combined near-infrared photothermia and drug delivery: Influence of pH and surface chemistry

“…An explanation is that at high concentrations, the penetration depth of the laser in the sample is limited due to light absorption by dispersion. [67,68] Thus the incident light cannot be equally distributed in the whole sample, as the NPs in the front of the cuvette would absorb and scatter most of the light. This leads to a gradient of incident power in the sample and in average the NPs absorb less.…”