大氣電漿沉積參數影響蛋白質薄膜特性之研究

Abstract

傳統蛋白質(或酶)嫁接成長於基材，常使用化學共價鍵合成法，但其缺點為步驟繁瑣，需配置化學溶液，易造成環境污染，及對人體有害，且該化學合成法需耗費多時。相關研究指出，使用大氣電漿聚合沉積蛋白質薄膜的方式，操作簡單，成膜反應時間短，既環保又省時。 本論文的目的為應用介電質放電平板式大氣電漿，沉積脂肪酶薄膜於矽晶圓基材(第1階段研究: 脂肪酶薄膜/矽晶圓)，探討工作電壓(kV)、工作頻率(kHz) 及陶瓷介電質板厚度(mm) 對脂肪酶薄膜特性之研究。使用傅利葉紅外光譜(FTIR)進行脂肪酶薄膜定性分析，掃描式電子顯微鏡 (SEM) 分析薄膜影像，EDS分析薄膜元素成份，及α-step量測薄膜厚度。研究結果顯示，陶瓷介電質板厚度為1 mm，分別改變工作電壓(3 kV, 4 kV) 及 工作頻率(4 kHz, 8 kHz)，顯示使用3 kV及4 kHz，脂肪酶薄膜經FTIR分析有較強的波峰，有較佳的蛋白質訊號。但是陶瓷介電質板厚度為1 mm，所沉積的脂肪酶薄膜，薄膜厚度較薄(~ 600 nm)，且碳鏈聚合不良，故薄膜附著性差。當陶瓷介電質板厚度為0.38 mm，工作電壓及工作頻率，分別為3 kV及4 kHz，沉積之脂肪酶薄膜，薄膜厚度較厚(~ 1200 nm)，碳鏈聚合優越，有優良的薄膜附著性，且FTIR顯示薄膜有較強的波峰，及較佳的蛋白質訊號。脂肪酶薄膜，經FTIR分析，SEM影像及EDS檢測有一致的結果。 為了改善脂肪酶薄膜附著不良的缺陷，本研究提出使用聚乙烯(PE)緩衝層，即第2階段研究:脂肪酶薄膜/聚乙烯薄膜/矽晶圓。研究顯示，使用聚乙烯緩衝層，經FTIR分析，脂肪酶的訊號Amide I (1640 cm-1)，C-O (1080 cm-1)及OH (3400 cm-1)峰值較高，薄膜附著性佳。使用聚乙烯緩衝層的脂肪酶薄膜，經FTIR分析， SEM影像及EDS檢測結果，有一致的趨勢。此外、本研究所形成的脂肪酶薄膜，存在有適當的活性。

Covalent bonding is traditionally used for the grafting and growth of protein (or enzyme) on substrate. However, the steps are long and tedious and require formulation of chemical solutions that may lead to environmental pollution and harm to human bodies. In addition, this chemical synthesis process takes a long time to complete. Studies have shown that the deposit of protein membrane by atmospheric pressure plasma features easy to use and shorter reaction time for membrane generation. It is environmentally friendly and time saving. This study is intended to investigate the influence of various parameters, including working voltage (kV), working frequency (kHz) and the thickness of ceramic dielectric plate (mm), on the characteristics of lipase membrane for the application of plate-type atmospheric-pressure plasma on the deposit of lipase membrane on silicon wafer substrate (Stage 1 study: lipase membrane / silicon wafer). Fourier transform infrared (FTIR) spectroscopy is employed for the qualitative analysis of the lipase membrane, scanning electron microscope (SEM) for image analysis of the membrane, EDS for the analysis of the membrane composition, and α-step for the measurement of membrane thickness. The analyses are performed with ceramic dielectric plate or 1 mm, working voltage of 3 kV and 4 kV, and working frequencies of 4 kHz and 8 kHz. The FTIR analysis indicates greater peaks and better protein signals for the lipase membrane at 3 kV and 4 kHz. However, with 1 mm of ceramic dielectric plate, the thickness of lipase membrane deposited is relatively thin (~ 600 nm) and the polymerization of carbon chains is less than satisfactory, thus poor coherence of membrane. When the thickness of ceramic dielectric plate at 0.38 mm and the working voltage and frequency at 3 kV and 4 kHz, respectively, the lipase membrane deposited is thicker (~ 1200 nm) with better polymerization of carbon chains and therefore membrane coherence. Also, FTIR indicates stronger peaks and better protein signals. For the lipase membrane produced, the analyses with FTIR, SEM and EDS produce consistent results. As an improvement for the poor coherence of lipase membrane, a polyethylene (PE) buffer layer is proposed, which is the Stage 2 study: lipase/PE membrane/silicon wafer. The FTIR analysis suggests that the addition of the PE buffer layer results in greater peaks for the lipase signals of Amide I (1640 cm-1), C-O (1080 cm-1) and OH (3400 cm-1), and better membrane coherence. For the lipase membrane with PE buffer layer incorporated, the analyses with FTIR, SEM and EDS produce consistent results. In addition, the lipase membrane produced in the study features appropriate activity.