Using Rapid Thermal Annealing Fabricated Localized Surface Plasmon Resonance Sensor for Multiple Biomarkers Detection

表面電漿共振是近年來在奈米光學領域內相當熱門的研究課題，因其具有免標定、非侵入式且高靈敏度等優點，常被應用在化學或生物感測器上，而侷域型表面電漿共振因為光學架構設計較為簡易且適用於即時性的量測，其相關研究獲得了廣泛的關注。本論文以檢驗抗體抗原的專一性鍵結為出發點，開發了一製程簡單且快速，且可大面積製作(2cm x 2cm)的侷域型表面電漿共振奈米金膜生物感測器，使用電子束蒸鍍以及快速熱退火來製作隨機分布的金奈米粒子結構，藉由調整三種製程參數：(1)鍍膜厚度；(2)退火溫度及(3)退火時間來做出不同尺寸與間距的金奈米粒子結構，並利用UV-VIS光譜儀以及原子力顯微鏡來量測奈米金膜的吸收光譜和表面結構。從量測結果中得出6-10nm的奈米金膜經過5分鐘900°C下的熱退火後會有較尖銳的吸收波峰，再從不同濃度的葡萄糖溶液實驗中得知10nm退火後的奈米金膜有最高的折射率靈敏度161.5 nm/RIU，且有較為一致的表面結構與吸收光譜(波峰位置差距< 1%)。為了更進一步研究隨機形狀與排列之金奈米粒子結構所產生的侷域型表面電漿共振電磁場和吸收光譜，本研究以原子力顯微鏡所得到的量測結果為基準，在有限元素分析軟體COMSOL上建立了一個等效的金奈米粒子陣列模型，來模擬並以數值方式計算經過不同條件的退火後，金奈米粒子的尺寸改變對吸收光譜造成的影響，未來可藉此微調退火參數。最後，本研究整合此侷域型表面電漿共振感測晶片和一商用的微流道晶片，達成了一個微型化的免疫分析系統，進行動態且連續性的多重細胞因子檢測，並維持良好的專一性與靈敏度且減少樣本需求(45μl)，未來若能再將光學架構微縮並整合，將可實現定點照護的理念。Surface plasmon resonance is a hot research topic in nanooptics field recently. Due to its label-free, non-invasive and highly sensitive merits, localized surface plasmon resonance based sensing techniques have been widely utilized in chemical or biosensing applications with simplified optical settings and real-time detection capability. In this paper, we developed a simple and fast nanostructure fabrication method using electron beam evaporation deposition and rapid thermal annealing (RTA) treatment to fabricate a large-area (2cm x 2cm) biosensor utilizing localized surface plasmon resonance (LSPR) nanoplasmonic effects. To get the best LSPR sensing performance of the gold nanostructure, we adjusted three fabrication conditions: (1) deposition thickness; (2) annealing temperature and (3) the annealing time. We then observed the absorbance spectrum profile and surface morphology using the UV-VIS spectrometer and atomic force microscopy (AFM). Based on the results, we discovered that the fabrication conditions at 6-10nm gold deposition under 900°C RTA treatment for 5 minutes shows sharper and stronger absorbance spectrum. We then test the sensitivity of these sensor by using glucose-water solution of different concentration. We found out that the 10nm gold chip shows the highest sensitivity 161.5 nm/RIU and holds a fine uniformity (peak wavelength variation < 1%). To study the electromagnetic field and the absorbance spectrum of the arbitrary-shaped and random-distributed nanoparticles fabricated by RTA treatment, we constructed an effective nanostructure array based on AFM scanned results and used a finite-element method (FEM) software COMSOL to numerically analyze the dependence of absorbance spectrum on the different height of nanoparticles for future alternation of annealing parameters. Finally, we integrated this LSPR sensor with a commercial microfluidic channel as an immunoanalysis platform to achieve dynamic and continuous detection of multiple cytokines with reduced sample volume (45μl) while still demonstrating fine specificity and sensitivity. In the future, if we can minimize the optical structure and integrates it into the system, we will be able to realize the point-of-care testing approach