Strong Photoacoustic Signal Enhancement by Coating Gold Nanoparticles with Melanin for Biomedical Imaging
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
Photoacoustics is a powerful biomedical imaging and detection technique, because it is a noninvasive, nonionizing, and low-cost method facilitating deep tissue penetration. However, suitable contrast agents need to be developed to increase the contrast for in vivo imaging. Gold nanoparticles are often discussed as potential sonophores due to their large absorption cross-section and their tunable plasmon resonance. However, disadvantages such as toxicity and low photoacoustic efficiency in the tissue transparency window prevail, preventing their clinical application. As a result, there remains a strong need to develop colloidal photoacoustic contrast agents which absorb in the tissue transparency window, exhibit high photoacoustic signal, and are biocompatible. Here, a facile synthetic approach is presented to produce melanin shells around various gold nanoparticle geometries, from spheres to stars and rods. These hybrid particles show excellent dispersability, better biocompatibility, and augmented photoacoustic responses over the pure melanin or pristine gold particles, with a rod-shape geometry leading to the highest performance. These experimental results are corroborated using numerical calculations and explain the improved photoacoustic performance with a thermal confinement effect. The applicability of melanin coated gold nanorods as gastrointestinal imaging probes in mouse intestine is showcased.
Details
Original language | English |
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Article number | 1705607 |
Journal | Advanced functional materials |
Volume | 28 |
Issue number | 7 |
Publication status | Published - 14 Feb 2018 |
Peer-reviewed | Yes |
Keywords
ASJC Scopus subject areas
Keywords
- contrast agents, core-shell particles, intestinal imaging, photothermal, thermal confinement