title: Nanoscale heating of laser irradiated single gold nanoparticles in liquid.
abstract: Biological applications where nanoparticles are used in a cell environment with laser irradiation are rapidly emerging. Investigation of the localized heating effect due to the laser irradiation on the particle is required to preclude unintended thermal effects. While bulk temperature rise can be determined using macroscale measurement methods, observation of the actual temperature within the nanoscale domain around the particle is difficult and here we propose a method to measure the local temperature around a single gold nanoparticle in liquid, using white light scattering spectroscopy. Using 40-nm-diameter gold nanoparticles coated with thermo-responsive polymer, we monitored the localized heating effect through the plasmon peak shift. The shift occurs due to the temperature-dependent refractive index change in surrounding polymer medium. The results indicate that the particle experiences a temperature rise of around 10 degrees Celsius when irradiated with tightly focused irradiation of ~1 mW at 532 nm.
authors.affiliation: Department of Applied Physics, Osaka University, Osaka, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Honda
authors.forename: Yuika
authors.initials: Y
authors.lastname: Saito
authors.forename: Nicholas I
authors.initials: NI
authors.lastname: Smith
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Fujita
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kawata
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000180:Acrylic Resins; D003585:Cell Biology / Q000295:instrumentation; D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D006358:Hot Temperature; D007834:Lasers; D008027:Light; D008853:Microscopy / Q000295:instrumentation / Q000379:methods; D008962:Models, Theoretical; D053758:Nanoparticles; D036103:Nanotechnology / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D012031:Refractometry / Q000295:instrumentation / Q000379:methods; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000295:instrumentation / Q000379:methods; D014466:Ultraviolet Rays
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D006046:Gold