使用經聚對二甲苯修飾之表面電漿子共振系統開發A型流感病毒免疫感測器之研究

Abstract

本研究目的為開發一偵測A型流行性感冒的表面電漿子共振免疫感測器系統，為能增加此系統之穩定度及提高其系統靈敏度，本研究將發展一披附有di-para-xylene (Parylene)此種高分子化合物之表面電漿子共振系統。此系統結合具有表面ㄧ致性、低介電常數、電子穩定特性之Parylene與已廣泛應用之高靈敏度表面電漿子共振系統(surface plasmon resonance, SPR)，以期能提高SPR系統之靈敏性與穩定性。本研究首先進行SPR系統之基礎特性探討，逐項討論系統中所使用的奈米金微粒(nanogold particles)的光學性質、電漿處理功率、電漿氣體混合比例、最適固定化條件等。在本研究中使用疏水性電漿進行Parylene表面改質，再利用矽烷類於系統表面形成具有游離胺基官能基之自組裝單層膜 (self-assembled monolayer, SAM)，以靜電吸附奈米金微粒，製成實驗所需之晶片。隨後將探討何種連結劑 (linker) 最適合做為本系統固定抗體所用，研究中所討論之連結劑為3-MPA (3-mercaptopropionic acid)、11-MUA (11-Mercaptoundecanoic acid)、和16-MHA (16-Mercaptohexadecanoic acid)，這三種不同碳數之連結劑，其結構一端為硫醇基((thiol group,-SH group)；另一端為羧基(carboxyl group,-COOH)，故能用-SH group與奈米金微粒形成硫金鍵固定於晶片表面，再經EDC/NHS (N-Ethyl-N'-(3-dimethylaminopropyl)carbodiimide polymer/ N-Hydroxysuccinimide)催化，使-COOH group能與抗體以醯胺鍵 (amide bond）結合，達到固定化抗體的效果。為能再增加此系統之靈敏及實用性，本研究配合半導體製程，以光阻在晶片表面製作出光柵，配合表面電漿處理，即可進行表面選擇性改質，於晶片表面修飾出奈米金微粒的光柵圖型。本研究所開發出的SPR系統具有成本低廉、使用方便、偵測快速、且不須外加標籤物 (non-labeling)等優點，可將此系統應用在其他生物檢測相關領域上。

In this thesis, we try to develop a new surface plasmon resonance (SPR) immunobiosensor to detect Influenza A/ H1N1. We combine di-para-xylene (Parylene) and the SPR system to enhance the system stability and sensitivity. Parylene has the property of surface regularity, low permittivity, electric stability, and biocompatible. It is hydrophobic and it can resist the damage caused by acid and bases. Those characters make it a good physical, chemical, and biological barrier material. Because Parylene is very stable material, we use hydrophobic plasma to modify the surface of Parylene chip. Silano compound has a positive electricity group end and can form a self-assembled monolayer (SAM) on the chip. The nanogold particals were attracted to the silano surface by the static electricity. Then we used different linkers to immobilize the antibody to make the SPR chip. The linkers are 3-MPA (3-mercaptopropionic acid), 11-MUA (11-Mercaptoundecanoic acid) and16-MHA (16-Mercaptohexadecanoic acid). They have different number of carbon but have similar structure that one end is thiol group which can form S-Au bond, and the other end is carboxyl group. The immobilization of antibodys were carried gut by activation of the surface carboxyl groups with NHS (N-Hydroxysuccinimide) and EDC (N-Ethyl-N'-(3-dimethylamino- propyl)carbodiimide polymer) to form the NHS ester and by displacement of the NHS ester with an amino group on the antibody to form an amide bond. Furthermore, we used mask to make a grating on the chip to improve the reactivity. The SPR system offer many advantages including cheap, resisting electric interference, stable, and high reactivity. According to our study, the system has the potential to operate in complex condition, and it could apply other model biosensor for epidemic control and clinical detection.