講演情報
[19p-A602-6]Surface Phonon Resonances in Circular Cavities on the Surface of Bioactive Hydroxyapatite for Biosensing Platforms
〇(DC)Shuting Ma1, Tang Dang1, Hidehiko Yoda2, Yoshita Sato1, Hitoshi Tabata1, Hiroaki Matsui1 (1.The Univ. of Tokyo, 2.Utsunomiya Univ.)
キーワード：
surface phonon resonance、hydroxyapatite、circular cavities
Surface phonon resonance (SPhR) occurs when the collective oscillations of atomic lattice are excited by external incident fields from mid-infrared (MIR) range at the surface of a polar dielectric. SPhR-related phenomenon in the IR range is connected to surface-enhanced infrared absorption (SEIRA) toward spectroscopic measurements through the coupling between the molecular vibrations and SPhRs, leading to biosensing devices with label-free molecular recognition for monitoring biological interactions. The SPhRs of classical phononic materials such as SiC, h-BN and alumina have higher Q-factors than those of plasmonic materials, however, the sensing of these materials is limited to the target molecules. In contrast, this research focused on a well-known bioactive material, hydroxyapatite (HAp), which actively interacts with the surrounding liquid environment resulting in the change of surface status. The environment-sensitive nature of surface phonons makes it possible to function as active optical probes, defining as “active SEIRA”. In this work, we fabricated a series of Au microhole arrays with different hole sizes on ceramic HAp substrates. SPhRs could be excited at around 1098 cm-1 in the Reststrahlen band only by p-polarization light. The surface phonon resonant Q-factors of HAp were higher than many classical phononic materials and could reach 163 at θ = 50°. Therefore, HAp had the potential to be one of candidates as phononic materials and SEIRA platforms. The purpose of this research is to create HAp as a novel biosensing platform based on active-SEIRA for detecting the chemical change of host surface dependent on environment (pH) and examining the affinity to polypeptides.