Photothermal detection of gold nanoparticles using phase-sensitive optical coherence tomography.
The detection of a gold nanoparticle contrast agent is demonstrated using a photothermal modulation technique and phase sensitive optical coherence tomography (OCT). A focused beam from a laser diode at 808 nm is modulated at frequencies of 500 Hz-60 kHz while irradiating a solution containing nanoshells. Because the nanoshells are designed to have a high absorption coefficient at 808 nm, the laser beam induces small-scale localized temperature oscillations at the modulation frequency. These temperature oscillations result in optical path length changes that are detected by a phase-sensitive, swept source OCT system. The OCT system uses a double-buffered Fourier domain mode locked (FDML) laser operating at a center wavelength of 1315 nm and a sweep rate of 240 kHz. High contrast is observed between phantoms containing nanoshells and phantoms without nanoshells. This technique represents a new method for detecting gold nanoparticle contrast agents with excellent signal-to-noise performance at high speeds using OCT.
Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Desmond C
DC
Adler
Shu-Wei
SW
Huang
Robert
R
Huber
James G
JG
Fujimoto
D006046:Gold / Q000032:analysis; D007089:Image Enhancement / Q000379:methods*; D007834:Lasers; D053758:Nanoparticles / Q000648:ultrastructure*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013696:Temperature; D041623:Tomography, Optical Coherence / Q000295:instrumentation / Q000379:methods*
D006046:Gold