Journal of Physical Chemistry & Biophysics
Open Access

Analysis of photoacoustic response from plasmonic nanostructures irradiated by ultrafast laser in water

International Conference and Trade fair on Laser Technology

July 20-22, 2015 Orlando, Florida, USA

Ali Hatef, Behafarid Darvish, Adrien Dagallier and Michel Meunier

Posters-Accepted Abstracts: J Phys Chem Biophys

Abstract :

Gold and silver plasmonic nanoparticles (NPs) are widely used as a contrast agent for photoacoustic imaging (PAI) which is taking the advantages of the strong optical absorption cross-section of these particles due to localized surface-plasmon resonance (LSPR). In the conventional PAI techniques, the NPs are irradiated by a high fluence nanosecond pulsed laser at the LSPR wavelength (on-resonance) that leads to high absorption of light. The main disadvantage of this technique is that the NPs are susceptible to melting and fragmentation since the temperature increase for such long pulses cannot be calibrated reliably, which can end up in undesirable biological effects. Inspired by recent developments in ultra-high frequency widebandwidth transducers that capable of detecting the ultra short pulses, in this talk we present a possible model to calculate photoacoustic response from NPs irradiated by a low fluence femtosecond (fs) pulsed laser. This technique has the potential to induce substantially larger amplitudes of the photoacoustic pressure signal than the conventional approaches. Additionally, such an irradiation has the capacity to avoid the aforementioned side-effects of high fluences on NPs. The reason is that the applied laser pulse duration (10 to 300 fs) is much shorter than the heat diffusion time of the materials, thus resulting in significantly less thermal shock or collateral damage of the laser-irradiated biological tissues.