反射式管狀波導粒子電漿共振生物感測平台之開發

Development of Reflection-Based Tubular Waveguide Particle Plasmon Resonance Biosensing Platform

黃昱中(Yu-Chung Huang)

指導教授 ： 周禮君

國立中正大學/理學院/化學暨生物化學系/碩士(2014年)

摘要

本研究之主要研究目的為，以管狀波導粒子電漿共振(tubular waveguide particle plasmon resonance, TW-PPR)生物感測器為基礎，發展出一套新穎之反射式管狀波導粒子電漿共振(reflection-based tubular waveguide particle plasmon resonance, RTW-PPR)生物感測平台。此系統是藉由給予固定激發波長的發光二極體(light emitting diode, LED)光源，導入光纖中進行多次全內反射傳遞，並可準確的耦合入中空玻璃管管壁內進行全內反射傳遞，而玻璃管內外壁修飾之金奈米粒子，藉著漸逝波現象產生粒子電漿共振，當奈米粒子因外在環境的變化(例如：環境折射率變化、奈米粒子表面修飾上不同生化分子，進行特異性吸附之生化反應)，則粒子電漿共振強度則會有所變化。而在本研究中，會在中空玻璃管尾端修飾一反射塗層，當光在管壁內開始進行傳導時，光會沿著管壁到達玻璃管尾端之反射塗層區，藉由反射塗層之反射，入射光可經由二次光學路徑之傳遞，使粒子電漿共振效應得到累加，造成光強度之下降量增加，可有效增加感測系統的靈敏度，最後再經由光纖傳導進入光二極體(photodiode, PD)進行偵測。此系統並不像傳統生物感測分析方法，需要額外對欲偵測之分子進行標定(例如：修飾螢光分子或二次抗體)，即可達到免標定、即時偵測、高靈敏度等優點。
論文中對系統之光學與感測元件進行優化，並對系統之穩定度、再現性、感測靈敏度與感測解析度以折射率變化之一系列實驗與生化檢測實驗進行分析與評估。在折射率實驗中利用配置不同濃度之蔗糖水溶液進行實驗，結果顯示平台對於折射率變化的感測解析度約為2.21x10-5 RIU，感測靈敏度為 -6.17 RIU-1。在生化檢測實驗上，利用卵白蛋白(ovalbumin, OVA)對卵白蛋白抗體(anti-OVA)進行檢測，經數據處理後，檢量線之迴歸係數(R2) > 0.99，偵測極限可達5.71x10-7 g/mL (3.81x10-9 M)，此結果成功的驗證了研究中開發之RTW-PPR生物感測平台之可行性。
學與感測元件進行優化，並對系統之穩定度、再現性、感測靈敏度與感測解析度以折射率變化之一系列實驗與生化檢測實驗進行分析與評估。在折射率實驗中利用配置不同濃度之蔗糖水溶液進行實驗，結果顯示平台對於折射率變化的感測解析度約為2.21x10-5 RIU，感測靈敏度為 -6.17 RIU-1。在生化檢測實驗上，利用卵白蛋白(ovalbumin, OVA)對卵白蛋白抗體(anti-OVA)進行檢測，經數據處理後，檢量線之迴歸係數(R2) > 0.99，偵測極限可達5.71x10-7 g/mL (3.81x10-9 M)，此結果成功的驗證了研究中開發之RTW-PPR生物感測平台之可行性。

關鍵字

漸逝波 ； 粒子電漿共振 ； 波導 ； 奈米金粒子 ； 生物感測器

並列摘要

The objective of this work is to develop a novel chemical and biochemical sensing platform, namely, a reflection-based tubular waveguide particle plasmon resonance (RTW-PPR) biosensing platform, which is based on the tubular waveguide particle plasmon resonance (TW-PPR) biosensor. The working principle of this invention is given by the following processes: 1. a light emitting diode (LED) emits light with an excitation wavelength corresponds to the particle plasmon resonance (PPR) of gold nanoparticle; 2. the light is transmitted by optical fibers and coupled into a glass tube; 3. the light traveled in the tube wall by multiple total internal reflections (TIRs); 4.The evanescent wave excites the PPR of gold nanoparticles on the surface of the tube wall. When the refractive index of the medium surrounding the nanoparticles changes (eg. adsorption of biomolecules on nanoparticle surface), the peak wavelength and extinction cross-section of the particle plasmon resonance (PPR) band changes.
To construct the sensor tube, the bottom of the tube will be modified with a reflective layer. When the incident light reaches the reflective layer, the light will travel to opposite direction. The PPR effect increases through an increase of optical path length by reflection, when the sensor length is the same, thus effectively enhances the sensitivity of the sensing system. The light is finally detected by a photodiode (PD) through fiber optics. This system does not require labeling (eg. modified fluorescent molecular). Hence, the RTW-PPR biosensing platform can achieve label-free and real-time detection with high sensitivity.
In this work, we optimized the optical and sensing elements of the system. System stability, reproducibility, sensor sensitivity and sensor resolution (SR) will be tested by a series of refractive index (RI) experiments and biochemical detection experiments. In the RI experiment, using different weight percents of sucrose in pure water, a refractive index resolution of 2.21x10-5 RIU and a sensor sensitivity of -6.17 RIU-1 have been achieved by the sensor. In the biochemical detection experiments, OVA were used to functionalize the gold nanoparticle in order to detect anti-OVA antibody. Results show that the calibration curve is linear (R2>0.99) and the limit of detection (LOD) is about 5.71x10-7 g/mL (3.81x10-9 M). In summary, we have developed a novel RTW-PPR biosensing platform successfully, and its feasibility in biosensing has been demonstrated.

並列關鍵字

particle plasmon resonance ； waveguide ； gold nanoparticles ； Evanescent wave ； biosensor

參考文獻

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