Picosecond photoacoustic generation of ultrasounds with composites of graphene-decorated gold nanoparticles

Vella, Daniele (avtor), Pereira, Diogo A. (avtor), Mrzel, Aleš (avtor), Vengust, Damjan (avtor), Drnovšek, Aljaž (avtor), Arnaut, Luís G. (avtor), Serpa, Carlos (avtor), Jezeršek, Matija (avtor)

Photoacoustic or light-to-pressure transducer materials exhibit tremendous potential across various disciplines and applications, embracing theragnostic ultrasounds and permeabilization of biological barriers for drug delivery or for gene transfection. Here, we report the photoacoustic response in the picosecond excitation regime of graphene and gold nanoparticles decorated graphene dispersed in a polydimethylsiloxane polymer matrix. A novel decoration method was developed to nucleate Au nanoparticles of 25 nm on the graphene surface without reducing agent. We observed that the picosecond excitation enforced by the stress confinement generates high-frequency waves, with bandwidths of −6 dB and −20 dB of around 70 MHz and 130 MHz respectively, and peak pressure > 5 MPa. Further, the presence of gold surface decoration leads to a better dispersibility of the flake into the polymer matrix and to an increasing bandwidth at −6 dB up to 85 MHz. The decrease in source thickness leads to an increase in ultrasound frequency, which retains its value even when the laser fluence is increased up to 150 mJ cm$^{–2}$. This enables the generation of high pressures while keeping the same bandwidth. We experimentally show that the photoacoustic waveform can be tailored by changing the temporal duration of the laser light, the geometry of the acoustic source, and the nature of the graphene absorber. Flexible decoration and fabrication methods of thin films, along with the generation of high-frequency and high-pressure ultrasound waves, offer new perspectives for the use of physical methods to permeabilize biological barriers and develop high-resolution photoacoustic imaging systems.

• Jezik: Angleški jezik
• Ključne besede: graphene composites, gold nanoparticles decoration, photoacoustics, high-frequency ultrasound, photoacoustic waves
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2024
• Št. strani: 12 str.
• Številčenje: Vol. 131, pt. A, art. 110236
• PID: 20.500.12556/RUL-162806
• UDK: 535
• ISSN pri članku: 2211-3282
• DOI: 10.1016/j.nanoen.2024.110236
• COBISS.SI-ID: 208436739
• Datum objave v RUL: 27.09.2024

Gradivo je del revije

• Naslov: Nano energy
• Založnik: Elsevier
• ISSN: 2211-3282
• COBISS.SI-ID: 138242563

Licence

• Licenca: CC BY-NC-ND 4.0, Creative Commons Priznanje avtorstva-Nekomercialno-Brez predelav 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by-nc-nd/4.0/deed.sl
• Opis: Najbolj omejujoča licenca Creative Commons. Uporabniki lahko prenesejo in delijo delo v nekomercialne namene in ga ne smejo uporabiti za nobene druge namene.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: grafenski kompoziti, dekoracija z zlatimi nanodelci, fotoakustika, ultrazvok, fotoakustično valovanje