Absorption efficiency of gold nanorods determined by quantum dot fluorescence thermometry

Abstract

In this work quantum dot fluorescence thermometry, in combination with double-beam confocal microscopy, has been applied to determine the thermal loading of gold nanorods when subjected to an optical excitation at the longitudinal surface plasmon resonance. The absorbing/heating efficiency of low (%3) aspect ratio gold nanorods has been experimentally determined to be close to 100%, in excellent agreement with theoretical simulations of the extinction, absorption, and scattering spectra based on the discrete dipole approximation. Gold nanorods (GNRs) are one of the most popular metallic nanoparticles with numerous applications in a great variety of fields including data storage, solar energy, catalysis, photonic devices, and microscopy.

Dynamic single gold nanoparticle visualization by clinical intracoronary optical coherence tomography

“…The absorption efficiency of any GNP is defined as the ratio between the absorption and extinction cross section, i.e. . This efficiency can be estimated by using the discrete dipole approximation method and, in particular, the open‐source Fortran‐90 software package DDSCAT 7.3 .…”

Photoluminescence thermometry with alkyl‐terminated silicon nanoparticles dispersed in low‐polar liquids

“…In addition, they possess serious disadvantages, such as: complex production process, toxicity, scarcity of material resource 6 and significant PL quenching for harsh environment applications. In current state‐of‐the‐art, typical thermal sensitivity values reported in the literature are: 0.8–0.9%/K for II–IV quantum dots 1, 7, PbF 2 :Er 3+ /Yb 3+ NPs – 1.0%/K 1, 8, Eu(tta)3L complex – 1.1%/K 1, C 70 ‐based thermometer – 1.3%/K, core‐shell ZnCdSe quantum dots – 1.3%/K 9. It is worth noting that some polymers (e.g.…”

Subtissue Imaging and Thermal Monitoring of Gold Nanorods through Joined Encapsulation with Nd‐Doped Infrared‐Emitting Nanoparticles

“…The extinction spectra of the ENSs and LaF 3 :Nd NPs aqueous dispersions consist in a wavelength decreasing background, together with absorption features of either the GNRs or Nd‐doped NPs. Nevertheless, it should be noted that for the case of the colloidal GNRs dispersion the background is not observed, as the extinction spectrum is clearly dominated by the typical transversal (≈520 nm) and longitudinal (≈800 nm) surface plasmon resonance bands of these nanorods . For the particular case of the GNRs used in this work an absorption efficiency σ abs /σ ext was found to be close to 0.95, so that they show a heating efficiency close to 1 .…”

“…In particular, gold nanorods (GNRs) display broad longitudinal extinction SPR bands between 700 and 1400 nm depending on their dimensions and aspect ratio . GNRs with a λ SPR close to 800 nm were reported having light‐to‐heat conversion efficiencies close to 1 . Unfortunately, GNRs do produce almost no luminescence except for a weak visible emission, generated by multiphoton laser excitation requiring ultrafast lasers, which is very useful for in vitro microscopy but of limited application for in vivo imaging .…”