Amplified photoacoustic performance and enhanced photothermal stability of reduced graphene oxide coated gold nanorods for sensitive photoacoustic imaging.
We report a strongly amplified photoacoustic (PA) performance of the new functional hybrid material composed of reduced graphene oxide and gold nanorods. Due to the excellent NIR light absorption properties of the reduced graphene oxide coated gold nanorods (r-GO-AuNRs) and highly efficient heat transfer process through the reduced graphene oxide layer, r-GO-AuNRs exhibit excellent photothermal stability and significantly higher photoacoustic amplitudes than those of bare-AuNRs, nonreduced graphene oxide coated AuNRs (GO-AuNRs), or silica-coated AuNR, as demonstrated in both in vitro and in vivo systems. The linear response of PA amplitude from reduced state controlled GO on AuNR indicates the critical role of GO for a strong photothermal effect of r-GO-AuNRs. Theoretical studies with finite-element-method lab-based simulation reveal that a 4 times higher magnitude of the enhanced electromagnetic field around r-GO-AuNRs can be generated compared with bare AuNRs or GO-AuNRs. Furthermore, the r-GO-AuNRs are expected to be a promising deep-tissue imaging probe because of extraordinarily high PA amplitudes in the 4-11 MHz operating frequency of an ultrasound transducer. Therefore, the r-GO-AuNRs can be a useful imaging probe for highly sensitive photoacoustic images and NIR sensitive therapeutics based on a strong photothermal effect.
Hyungwon
H
Moon
‡KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 136-701, South Korea.
Dinesh
D
Kumar
Haemin
H
Kim
Changbeom
C
Sim
Jin-Ho
JH
Chang
⊥Department of Electronic Engineering, Chonbuk National University, 567 Baeckje-daero, Jeonju 561-756, South Korea.
Jung-Mu
JM
Kim
Hyuncheol
H
Kim
‡KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 136-701, South Korea.
Dong-Kwon
DK
Lim
D000818:Animals; D004355:Drug Stability; D005260:Female; D020342:Finite Element Analysis; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D007259:Infrared Rays; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008968:Molecular Conformation; D043942:Nanotubes / Q000737:chemistry*; D055620:Optical Phenomena; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D061088:Photoacoustic Techniques / Q000379:methods*; D013696:Temperature
D010087:Oxides; D006046:Gold; D006108:Graphite
graphene-coated gold nanorods; photoacoustic imaging; photothermal effect