藉由直接於多晶矽線表面之細胞培養量測正常與癌細胞之電特性

Electrical Characterization of Normal and Cancer Cells by Culturing The Cells Directly on Polysilicon Wire Surface

王誌晟(Chih-Cheng Wang)

指導教授 ： 吳幼麟

共同指導教授 ： 徐中平

國立暨南國際大學/科技學院/生物醫學科技研究所/碩士(2009年)

摘要

在本論文中，我們提出一個基於多晶矽線結構的生化感測器來作為正常和癌細胞的偵測。將正常細胞和癌細胞直接培養在多晶矽線表面上，透過不同細胞之不同細胞膜電位會去累增或是減少矽線空乏區內的電荷而導致流過多晶矽線電流的不同。在本研究中，我們利用垂直爐管將多晶矽沉積在二氧化矽上，並使用電子束微影去定義多晶矽線圖案，經過顯影與乾式蝕刻後，再利用APTES (3-aminopropyltriethoxysilane)對矽線表面做化學處理來完成多晶矽線之製作。我們將人類肺纖維母細胞 (human lung fibroblast cell) WI-38，人類肺纖維細胞 (human fetal lung fibroblast cell) MRC-5，人類支氣管上皮細胞 (human bronchial epithelium cell) BEAS-2B和人類肺腺癌細胞 (human lung adenocarcinoma cell) A549、H1299，人類肺癌鱗狀細胞 (human lung squamous carcinoma cell) CH27，人類口腔鱗狀細胞癌 (human oral cancer cell) OCSL，人類絨毛膜癌細胞 (human choriocarcinoma cell) JAR等，直接培養於多晶矽線表面。經過細胞培養後，利用半導體參數分析儀HP 4156B量測通過多晶矽線之電流，藉此推斷正常細胞與癌細胞之膜電位。我們發現正常細胞所產生之電流較癌細胞之電流來的小。

此外，亦發現細胞膜電位大小與細胞貼附深度是有關係的。將正常細胞與癌細胞培養在經過APTES處理過之矽晶片上經過細胞移除之程序後，我們利用原子力顯微鏡觀察正常細胞與癌細胞留下之印痕深度。由於癌細胞具有侵犯和轉移之能力，相對其印痕深度遠比正常細胞大，故推斷癌細胞之膜電位對多晶矽線內可通過電流之影響比正常細胞來得大。

實驗數據顯示，所提出以多晶矽線為基礎之細胞電性感測器偵測人類正常細胞與癌細胞經由其I-V之量測確實可以用來偵測不同正常細胞與癌細胞之電性，並發現癌細胞電性會隨著時間增加而有降低之現象，相對於正常細胞而言則無此現象。此一模式更提供不需螢光標定之偵測方法，免去了螢光標定可能對細胞之影響。

關鍵字

多晶矽線 ； 細胞膜電位 ； 原子力顯微鏡 ； 正常細胞 ； 癌細胞 ； APTES

並列摘要

In this thesis, we proposed a biosensor based on polysilicon (poly-Si) wire structure for normal and cancer cells detection. We cultured the normal cells WI38 (human lung fibroblast cell), MRC5 (human fetal lung fibroblast cell), BEAS-2B (human bronchial epithelium cell) and the cancer cells A549 (human lung adenocarcinoma cells), H1299 (human lung adenocarcinoma cell), CH27 (human lung squamous carcinoma cell), OCSL (human oral cancer cell), JAR (human choriocarcinoma cell) directly on the poly-Si wire surface. In order to enhance the adhesion between the cells and the poly-Si wire surface, a 3-aminopropyltriethoxysilane (APTES) layer was coated onto the poly-Si surface. Since different cells exhibit different membrane potential, charge accumulation and/or depletion will be induced in the poly-Si wire channel when the cells are attached to the poly-Si wire surface, and thus the current flowing through the poly-Si wire will be modulated.

In this work, an n-type poly-Si layer was deposited on a p-type Si substrate with a thermally grown SiO2 layer on its surface. The poly-Si wire structure was then defined by using E-Beam lithography and RIE etching. After the surface modification by APTES, WI38, MRC5, BEAS-2B, A549, JAR, OCSL, H1299 and CH27 cells were separately cultured on the poly-Si wire surface. The current flowing through the poly-Si wire channel was then measured by using the semiconductor analyzer HP 4156B. Different electrical characteristics were found between the normal and cancer cells. The advantage of using poly-Si wire sensor is that it eliminates the drawback of the alignment issue in typical nanowire sensor using microfludic channel for solution transfer as well as that it is label free and the detection can be carried out in dry environment.

On the other hand, force exerted from the cells leave imprints on the APTES surface after the cells were removed. By taking advantage of its nanoscale resolution, atomic force microscopy (AFM) was used to detect the fine feature of the surface morphology changes caused by cell-substrate interaction in this work. Different cells leave imprints with different depth and width on the substrate, which reflects different cell-substrate interactions.

並列關鍵字

poly-silicon wire ； membrane potential ； atomic force microscopy ； normail cell ； cancer cell ； APTES

參考文獻

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