光子晶體微米柱陣列基板應用於生物微陣列晶片之設計與製造

Abstract

本研究的目的是要發展「光子晶體微米柱陣列基板」來增強螢光並減低背景雜訊，以期改善檢測極限。此基板將包含一個微米圓柱之陣列，並且每一圓柱頂端將具備光子晶體結構。光子晶體將用於增強螢光，微米圓柱之陣列將用於提高靈敏度與減低背景雜訊，初步將應用此基板於蛋白質陣列晶片。

本研究的光子晶體在功能上為一個光共振器，是一個包含高折射率介電質覆蓋在低折射率的光柵結構。在特定組合的入射波長及角度，將可激發結構之共振。在此共振模態下，將可產生~100%的反射，且電場將會集中於高折射率介電質並藉由漸逝波(evanescent wave)延伸至光子晶體表面。本研究將設計光子晶體使其共振模態與激發螢光分子之雷射光波長互相匹配，則光子晶體表面之近場電場，將透過漸逝波使其強度達數十倍之入射光所對應的電場強度，藉此來達到螢光增強之目的。

螢光增強的同時，將伴隨著背景雜訊之增大，本研究同時將設計一個微米尺度之圓柱陣列，來降低此效應。微米尺度之圓柱陣列，將使辨識分子之液珠與此陣列形成複合接觸(composite contact)，待完成螢光生物檢測實驗，每一個微柱將行成一個微點，藉由相鄰微柱之間隙，可將背景螢光移除或最小化。

本研究確立了光子晶體微米柱陣列基板的製作方式並將其製作出來，光子晶體微米柱陣列基板確實可做為微陣列基板使用，並且藉由實驗結果可得知光子晶體微米柱比微米柱陣列基板的螢光強度強了約4.5倍，然而背景雜訊並沒有隨之被放大。

The goal of this project is to develop a photonic crystal micropost (PCMP) substrate to enhance fluorescence and reduce background noise for further improvement of the limit of detection. The PCMP substrate consists of an array of microposts with photonic crystal (PC) structures on top of each micropost. The immediate applications will be DNA and protein microarrays. By spectrally matching the PC resonance with the excitation laser used to excite fluorophores, one can achieve increase in fluorophores’ emission due to an enhanced electric field. While the fluorescence are enhanced, inevitably the background noise will also be amplified. In this work, the micropost substrate consisted of an array of circular microposts was developed to eliminate or minimize the background noise. This substrate allows droplets (containing capture molecules) to form composite contact upon deposited on such surface. Upon finishing the assay, each micropost will serve as a spot. Due to the gap between micropost/spots, the background noise can be eliminated or minimized. In this study, we successfully establish an approach of fabricating the PCMP substrate. Also, we demonstrate that the PCMP can be used as a microarray substrate for enhancing fluorescence signal and minimizing the background signal. The results show that the fluorescence intensity on PCMP substrate can be enhanced by 4.5x. In contrast, the background signals are not amplified.