Measurement of temperature distribution and evolution during surface plasma resonance heating of gold nanoshells-embedded phantom tissue

Abstract

This paper presents an experimental study of temperature distribution and evolution in nanoshell colloidal solution and in phantom tissue populated with gold nanoshells under localized surface plasma resonance heating by an NIR laser. Gold nanoshells were synthesized in our laboratory and characterized using the TEM. Their optical properties were measured by a CARY 5000 photospectrometer and the localized surface plasma resonance occurs at 796nm. Two types of temperature measurement systems were used: one for the gold nanoshell colloidal solution and the other for nanoshell-populated phantom tissue. For both cases, heating was initiated by an NIR laser of 808nm. Measured data reveal that the temperature rises rapidly as a result of strong heating of gold nanoshells, which is converted from the absorbed laser energy under localized surface plasma resonance condition. Without nanoshell-mediated resonance absorption and heating, however, the temperature increase is practically negligible. The thermal transport mechanism in nanoshell-embedded tissue appears to be dominant by radiative heat transfer in the laser beam heating region but primarily by thermal conduction away from the laser beam.