[15p-C31-1~9] 4.2 Bio-and Medical Photonics

▲ [15p-C31-4] Development of A Localized Surface Plasmon Sensor with A Fabricated Sensing Surface Toward Multi-Analyte Detection

〇(M2)Kento Chiba¹, Kenichi Morigaki², Akira Ainai³, Hideki Hasegawa³, Koji Uwai¹, Hiroshi Kano¹ (1.Muroran Inst. of Technology, 2.Kobe Univ., 3.National Inst. of Infectious Diseases)

Keywords:surface plasmon refractive index sensor, virus detection, surface fabrication

Surface plasmons are recognized as one of the most sensitive probes for measuring refractive index on a sensing surface and intensively applied to detection of bio-related objects. We have also shown that a localized surface plasmon sensor is able to detect influenza viruses reacting to monoclonal antibodies fixed on the sensing surface. As a next step of our development, we fabricate sensing channels to detect multiple subtypes of the virus from one measurement. Since the size of surface plasmon localization is ~200 nm, the localized surface plasmons potentially enable parallel detection of multiple analytes from a sample with ultra-small volume. In this presentation, we propose a method to fabricate the sensing channels, and discuss the process of the fabrication. For implementing multiple sensing channels on the substrate, a method to fix certain ligands in a controlled and microscopic region is required. To this end, a fabrication method based on photochemical reaction is employed to change surface property in a selected microscopic region. Since an avidin surface is able to bind a wide variety of biotinylated ligands, photo fabrication to prepare avidin surface is our current target. At the first step of fabrication, 3-aminopropyltriethoxysilane (APTS) molecules are bound to the silica surface of a substrate. Then, 4,5-dimethoxy-2-nitrobenzylchloroformate (NVOC) is reacted with an amine group of APTS. NVOC is a removable molecule by irradiation of UV light, therefore, the amine groups are partly exposed by local irradiation of the UV light. Then, PEG4-Biotin and avidin are sequentially bound to the surface having amine groups. By using this method, we can bind biotinylated ligands at the location of UV irradiation. Repetition of this step produces multiple sensing channels for multi-analyte detection. To evaluate feasibility of the method, we monitored the varying refractive index during the fabrication process by using localized surface plasmon sensing. The measured refractive indices revealed that the reactions were properly proceeded including a post process of influenza virus detection. We confirmed local dissociation of NVOC by UV irradiation, as well.