[18a-A402-1~11] 3.12 Nanoscale optical science and near-field optics

△ [18a-A402-4] Surface plasmon resonance sensing interacting with molecular electronic transitions in far- and deep-ultraviolet regions

〇Ichiro Tanabe¹, Yoshito Tanaka², Watari Koji³, Taras Hanulia⁴, Takeyoshi Goto³, Wataru Inami⁴, Yoshimasa Kawata⁴, Yukihiro Ozaki³ (1.Osaka Univ., 2.Tokyo Univ., 3.Kwansei Gakuin Univ., 4.Shizuoka Univ.)

Keywords:surface plasmon resonance sensor, far-ultraviolet, electronic transition

Surface plasmon resonance (SPR) in the ultraviolet region attracts much attention because of the high energy and the various molecular electronic transitions compared to the visible region. In the present communication, SPR sensing with molecular electronic transitions was investigate, and enhancements of the SPR wavelength shift was revealed, by using an attenuated total reflectance (ATR) system in the far-ultraviolet (FUV, <200 nm) and deep-ultraviolet (DUV, <300 nm) regions. With an increase of the refractive index n on the aluminum (Al) film, the SPR wavelength shifted to the longer wavelength. By the effect of the absorbance (i.e. anomalous dispersion of the refractive index n) of N,N-dimethylformamide (DMF), the SPR wavelength shift was significantly increased compared to the materials with no absorbance such as water and alcohols. Au-based SPR wavelength shift showed no such enhancement since DMF also had no absorbance in the visible region. The enhanced shift due to the overlap between SPR wavelength and molecular resonance wavelength will lead to the label-free materials selectivity as the SPR sensor.