【研究成果】2012

研究成果52

Plasmonic resonance enhancement of single gold nanorod in two-photon photopolymerization for fabrication of polymer/metal nanocomposites
Kyoko Masui, Satoru Shoji, Feng Jin, Xuan-Ming Duan and Satoshi Kawata
APPLIED PHYSICS A: Volume 106, Number 4 (2012), 773-778, RAPID COMMUNICATION"

We investigated the plasmonic resonance enhanced two-photon photopolymerization (PETPP) using the isolated chemical synthesized gold nanorods for fabrication of polymer/metal nanocomposites. The isolated gold nanorods with the plasmonic resonance band around 750 nm covered by photoresist were irradiated by a femtosecond laser with the wavelength of 780 nm. The PETPP trigged by the plasmonic resonance enhancement of gold nanorods was localized only in the distance smaller than 30 nm from the surface of gold nanorods, which matched the distance of plasmonic resonant enhanced field of the gold nanorod. The shapes of obtained polymer/gold nanocomposites were changed from the “dumbbell” to the “ellipsoid” with the increase of laser irradiating intensity used for PETPP: the refractive index around the gold nanorod could be changed with the progress of PETPP as the refractive index of the solidified photoresist would be slightly increased after photopolymerization. This change of refractive index from the plasmonic resonance enhanced polymerization of photoresist might occur from the surface area of gold nanorod with strong field enhancement, and lead the new edge forming between the polymer and the surface of gold nanorod and then change the shape of polymer/gold nanocomposites. This study would provide a potential method for fabricating the plasmonic nanomaterials and nanostructures of polymer/metal nanocomposites, which could be expected to be applied in the emerging fields such as anophotonics, nanobiosensor, nanolithography.

Typical SEM images of the PMMA coated Au nanorods with different laser intensity, (a) 1.7 GW/cm2, (b) 3.1 GW/cm2, (c) 3.7 GW/cm2, (d) 4.5 GW/cm2. The scale bar is 100 nm. (e) The thickness of polymer layers covered on the Au nanorods in parallel (black squire) and perpendicular (red dot) directions on the laser intensity. Inset is the schematic of P∥ and P ⊥

(a) Plasmonic field enhancement pattern and (b) contour lines of field strength of the Au nanorods calculated at the 784 nm wavelength