聚乙烯對苯二甲酸酯絕緣層之胺化最佳化研究

Abstract

在以單面銅箔基板與胺基改質的聚乙烯對苯二甲酸酯（Polyethylene Terephthalate，PET）薄膜為絕緣體的低成本生物感測器中，胺基改質過程是製作感測器中的重要組成。為了進行表面改質之最佳化，使絕緣層表面胺基密度提高，需要開發一個方法來進行薄膜胺基之定量。本研究利用三氟乙酸（2,2,2-Trifluoroacetic acid，TFA）溶解PET薄膜，並使用 2,4,6-三硝基苯磺酸（2,4,6-trinitrobenzenesulfonic acid，TNBSA）與胺基反應生成一種黃色衍生物—N-三硝基苯胺，此物質可在335nm處測量吸光度。以0.1M 碳酸鹽緩衝液 （pH=9.0）泡製標準品並於1\mug/mL-30\mug/mL之 3-氨基丙基三乙氧基矽烷（3-Aminopropyltriethoxysilane，APTES）範圍內中建立具有高線性關係 （R^2>0.99） 的胺基檢量線，同時也確保三氟乙酸不影響TNBSA對胺基之檢量。該方法可以替代以往常用的測定胺基的其他比色法—橘色二號染色法（Orange II）。本研究選擇了乙二胺（1,2-diaminoethane，EDA）、三（2-氨基乙基）胺（triaminotriethylamine，TAEA）和3-氨基丙基三乙氧基矽烷（3-Aminopropyltriethoxysilane，APTES）作為材料，使用類「三明治模型」來進行PET薄膜胺化。比較不同反應溫度和時間以達到胺基改質PET薄膜的最佳化，並比較TNBSA及橘色二號染色法方式的量化結果。結果表明，在肉眼可見PET薄膜結構不損壞下，使用乙二胺在 55\degc下反應20 分鐘後，所得之每平方毫米的胺基密度最大，為5.998\times{10}^{-9}mol/{\rm mm}^2。

Amino-functionalizing procedure was an important part of capacitive biosensors manufactured by the single-sided copper-clad of PCB (Printed circuit board) and the PET (Polyethylene Terephthalate) film with amino-functionalized as insulators. As a result, amino-functionalized process is an important part of manufacturing. To optimize the surface modification, we need a protocol to quantify the amino density on the film. We dissolve the PET film with TFA (2,2,2-Trifluoroacetic acid) and use the TNBSA (2,4,6-trinitrobenzenesulfonic acid) which reacts with primary amine and generates N-trinitrophenylamines, a yellow derivative that can be measured absorbance at 335nm. We establish a linear calibration curve of amine with 1ug/ml-30ug/ml APTES (3-Aminopropyltriethoxysilane) in 0.1M carbonate buffer and make sure that TFA would not affect the calibration. The method can substitute other colorimetric methods. Orange II method was commonly used for quantifying amino groups, but it is hard to get Orange II salt as it is a toxic chemical substance. We choose EDA (1,2-diaminoethane) and APTES as material and used a kind of “sandwich model” treatment to modify the PET film and compare different reaction temperature and time to optimize the modification of amino-functionalized PET film. In consideration of the film integrity after amino-functionalized, the results suggest that 20 minutes of reaction time in 55\degc has the most amino-group density per square millimeter.