TY - JOUR
T1 - Theoretical and Experimental Study of Photoacoustic Excitation of Silica-Coated Gold Nanospheres in Water
AU - Pang, Genny A.
AU - Poisson, Florian
AU - Laufer, Jan
AU - Haisch, Christoph
AU - Bossy, Emmanuel
N1 - Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2020/1/9
Y1 - 2020/1/9
N2 - Silica-coated gold nanoparticles are commonly employed in biomedical photoacoustic (PA) imaging applications. The PA signal generation by silica-coated gold nanospheres in water was investigated theoretically and experimentally. The influence of interfacial thermal (Kapitza) resistance at the gold-water boundary and the influence of the silica coating on PA signal generation were investigated with a theoretical model considering thermoelastic expansion and a finite-difference in time domain solution to the thermoelastic equations. Our results indicate that for the several-nanosecond long pulses commonly employed in PA imaging, Kapitza resistance has a negligible effect on PA signal generation. Moreover, the model shows that the presence of a silica coating causes a reduction in the PA signal amplitude, with the magnitude of signal reduction increasing with thicker silica coating. The theoretical predictions are qualitatively consistent with the experimental results, where suspensions of silica-coated gold nanosphere suspensions were excited with nanosecond-pulsed laser illumination. The PA signal amplitudes from silica-coated nanospheres were found to be lower than the signal amplitudes for uncoated gold nanospheres of the same core gold diameter. The amount of reduction of the measured PA signal amplitude due to the silica coating increases with thicker silica coating, in agreement with the theoretical predictions.
AB - Silica-coated gold nanoparticles are commonly employed in biomedical photoacoustic (PA) imaging applications. The PA signal generation by silica-coated gold nanospheres in water was investigated theoretically and experimentally. The influence of interfacial thermal (Kapitza) resistance at the gold-water boundary and the influence of the silica coating on PA signal generation were investigated with a theoretical model considering thermoelastic expansion and a finite-difference in time domain solution to the thermoelastic equations. Our results indicate that for the several-nanosecond long pulses commonly employed in PA imaging, Kapitza resistance has a negligible effect on PA signal generation. Moreover, the model shows that the presence of a silica coating causes a reduction in the PA signal amplitude, with the magnitude of signal reduction increasing with thicker silica coating. The theoretical predictions are qualitatively consistent with the experimental results, where suspensions of silica-coated gold nanosphere suspensions were excited with nanosecond-pulsed laser illumination. The PA signal amplitudes from silica-coated nanospheres were found to be lower than the signal amplitudes for uncoated gold nanospheres of the same core gold diameter. The amount of reduction of the measured PA signal amplitude due to the silica coating increases with thicker silica coating, in agreement with the theoretical predictions.
UR - http://www.scopus.com/inward/record.url?scp=85078228145&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.9b09040
DO - 10.1021/acs.jpcc.9b09040
M3 - Article
AN - SCOPUS:85078228145
SN - 1932-7447
VL - 124
SP - 1088
EP - 1098
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 1
ER -