DIAGNOSIS PLATFORMS AND DIAGNOSIS METHODS USING SURFACE-ENHANCED RAMAN SCATTERING

생화학 물질 진단 플랫폼은 금속 나노 플레이트, 금속 나노 플레이트의 표면 상에 부착된 바이오 리셉터, 바이오 리셉터에 의해 포획된 바이오마커, 바이오마커를 캡핑하는 금속 나노 입자, 및 포획된 바이오마커를 분석하기 위한 분광 검출부를 포함한다. 바이오마커를 샌드위치시켜 고정함으로써 고민감도로 생화학물질을 검출할 수 있다

METHOD OF FABRICATING AN AuAg Single Crystal NANOWIRE

금은 합금 나노선의 제조 방법에 있어서, 기판 상에 금 나노선을 형성한다. 금 나노선 상에 은 증기를 공급한다. 기상 합성법에 의해 금은 합금 구조의 나노선을 형성하여 높은 화학적 안정성과 표면 플라즈몬 특성을 갖는 나노선을 제조할 수 있다

OPTICAL NANO ANTENNA USING SINGLE-CRYSTALLINE AG NANOPLATE, AND NANO OPTICAL EQUIPMENT INCLUDING THE SAME

본 발명은 단결정 은 나노판(Single-Crystalline Ag Nanoplate)를 포함하는 광학 나노 안테나로서, 상기 은 나노판의 일측단부에 위치하며, 입사광을 수신하는 수신단과 상기 은 나노판의 타측단부에 위치하며, 은 나노판의 표면을 따라 전파되는 표면플라즈몬-폴라리톤(SPP)파를 송신하는 송신단이 분리되어 위치하고, 상기 은 나노판의 표면을 따라 상기 수신단에서 수신된 입사광에 의해 유발되는 표면플라즈몬-폴라리톤(SPP)파가 전파되어 상기 송신단으로 전달되는 것을 특징으로 하는 광학나노 안테나에 관한 것이다

질병 조기진단을 위한 초고감도 플라즈모닉 나노센서 개발

학위논문(박사) - 한국과학기술원 : 화학과, 2014.2 ,[x, 108 p. :]In this study, we have fabricated highly reliable nano-plasmonic sensors with ultrasensitivity employ-ing single-crystalline noble metal nanostructures. For clear demonstration, This thesis consists of two main parts with 4 chapters. The first and main part demonstrates the early-diagnosis studies of acute myocardial infarction (chapter 1) and rheumatoid arthritis (chapter 2) employing Au particle-on-plate SERS sensor. Sin-gle-crystalline Au nanopate with ultraflat and ultraclean surface provides only very weak zero-signal due to highly reduced non-specific bindings, playing an important role in preparation of ultrasensitive sensor. The second and preliminary part reports fabrication of unique plasmonic platforms employing single-crystal AuAg nanowire (chapter 3) and Ag nonoplate optical antenna (chapter 4). The optical properties of AuAg alloy nanowires allow us to find a simple method to combine good plasmonic character of Ag and good corrosion resistant character of Au. Single-crystal Ag nanoplate can naturally involve plasmonic nano-antennas and SPP-active surface on a built-in platform. The detailed descriptions for each chapter are as follows. In chapter 1, we firstly discovered single strand DNA aptamers that can bind a cTnI as 77 times stronger than typical troponin antibodies using Systematic Evolution of Ligands by Exponential enrichment (SELEX) method and fabricated ultrasensitive SERS aptasensor with sub-fM of detection limit from troponin aptamer modified single-crystalline Au NPL-Au NP assembly. Since an ultra-flat surface of Au NPL is able to introduce a highly well-ordered self-assemble monolayer (SAM) of probe aptamers, non-specific binding is notably suppressed compared to NPs aggregation system so that zero-signal intensity at 0 M of cTnI detection can be extremely reduced. As a result, the Au NPL based SERS aptasensor will play an important role in development of a system for prognosis or prophylaxis against AMI from its reliable ultra-sensitivity and selectivity. In chapter 2, we reports ultrasensitive sensor with fM level of detection limit for anti-CCP, the best bi-omarker for rheumatoid arthritis, employing CCP modified Au particle-on-plate SERS platform. The anti-CCP was captured by sandwich method inserted at between Au NPL and Au NPs, creating hot spot from them to enhance Raman signal strongly. Especially, on ultraflat surface of Au, until 40 aM of anti-CCPs could be analyzed quantitatively with SEM observation, which was impossible on rough surface of Au film. We expect that such a highly well-defined SERS platform combining Au NPL and Au NPs can contribute importantly to fabrication of early-diagnosis tool against rheumatoid arthritis. In chapter 3, topotaxial growth of $Au_xAg_{1- x}$ alloy NWs by postepitaxial deposition of Ag vapor on Au NWs and investigation of their plasmonic properties are reported. Ag vapor is supplied onto the epitaxially grown Au NWs, topotaxially turning them into $Au_xAg_{1- x}$ alloy NWs. The original geometries and alignments of the Au nanostructures are well preserved, while the composition of the alloy NWs is controlled by varying the Ag vapor supply time. The $Au_{0.5}Ag_{0.5}$ NWs show high SERS activity comparable to that of Ag NWs as well as highly increased oxidation resistance. The plasmon-active wavelength range of the $Au_{0.5}Ag_{0.5}$ NW is significantly extended to the blue region compared to Au NWs. The $Au_xAg_{1- x}$ alloy NWs that have plasmonic activity in the blue region in addition to high corrosion resistance will make a superb material for practical plasmonic devices including SERS sensors and optical nanoantennas. In chapter 4, we have epitaxially synthesized twin-free single-crystal Ag nanoplates on $SrTiO_3$ sub-strates. Unlike the nanoplates synthesized in a solution phase, these nanoplates have perfectly clean surfaces as well as a quite large size of tens of micrometers. As-synthesized defect-free single-crystal Ag nanoplates have an atomically flat surface and sides with well-defined angles, allowing long distance propagation of surface plasmons and highly-reliable plasmonic integration. By spatially separating receiving and transmit-ting antennas and plasmonically interfacing them, it can highly improve the signal quality of transmis-sion/reception. Furthermore, by combining sub-dimensional nanostructures onto the two-dimensional space it can build up effective hierarchical plasmonic nano-complexes. Theoretical simulations well reproduced unique experimental results of coupling between SPPs and free-space radiation by the nanoplate antenna sides, low-loss long-range SPP propagation, and tunneling or scattering of SPPs at a nano-gap as well as a nano-structure introduced on the nanoplate. The single-crystal Ag nanoplate will find superb applications in plasmonic nano-circuitry and lab-on-a-chip for biochemical sensing.한국과학기술원 :화학과