On the quantitative optical properties of Au nanoparticles embedded in biological tissue phantoms

TL;DR

This study quantitatively analyzes how gold nanoparticle optical spectra change within biological tissue phantoms, providing insights crucial for optimizing plasmonic applications like therapy and gene circuits.

Contribution

It offers a systematic quantification of AuNPs spectral shifts and resonance changes in tissue phantoms, advancing understanding of their plasmonic behavior in biological environments.

Findings

Resonance peak positions shift with particle size and concentration.

Spectral broadening correlates with nanoparticle agglomeration.

Optical properties depend on local environment and particle distribution.

Abstract

We systematically investigated and quantified how gold (Au) metal nanoparticles (NPs) optical spectra change upon introduction into biological tissue phantoms environment, in which the AuNPs can agglomerate. Quantitative knowledge of how the AuNPs spectra and plasmon resonance wavelength change inside a phantom environment can provide many in-vitro and in-vivo plasmonic NPs-mediated applications. Because the plasmonic properties of metal NPs are dependent on their size, morphology, concentration and local environment, tuning the incident photon wavelength may increase the AuNPs plasmonic properties, on which applications such as plasmonic photothermal therapy and photonic gene circuits are based. Quantitatively analyzing optical absorption and scattering data, we were able to observe changes in the resonance peak positions and breadths, which are related to the distribution of the spherical AuNPs within the chitosan phantoms as a function of the particles size and concentration.