聚胜肽薄膜的合成及應用

Abstract

本篇論文中，我們利用了 (Surface-initiated vapor deposition-polymerization (SI-VDP)) 此高效率的薄膜成長技術，在矽、石英及金的基板上成功的成長了PCBL、PLL、PBLG及PLGA等聚胜肽薄膜，並用此薄膜來做後續之應用。 首先，我們利用PLL薄膜做為模板來催化tetraethoxysilane的聚合沉積反應，用此仿生反應來形成氧化矽奈米結構。在PLL薄膜的催化下，氧化矽可在常溫、中性的pH值下自發生成。而形成的氧化矽結構和PLL聚胜肽模板膜厚及橫向的微米圖形相當一致。此外，透過調控PLL聚胜肽模板的膜厚及疏密度，還可微調氧化矽奈米結構，令其結構由連續性的薄膜轉變為分離的球狀結構及纖維網狀結構。在利用高溫移除PLL聚胜肽模板後，在穿透式電子顯微鏡(TEM) 下可發現，用此方法可在表面上製造出平均約10奈米的細微通道。我們的方法提供了一個簡單容易且環保的方式，用以形成可調控形、貌厚度與疏密度的氧化矽奈米結構。 其次，我們成功的利用調控聚胜肽的排列及α螺旋與表面的傾斜角，形成在±0.422V下整流效應達約122的分子二極體。在此，我們利用SI-VDP在金的表面成長PBLG 聚胜肽薄膜並利用solvent-quenching的方式(先以chloroform浸泡薄膜讓PBLG分子鍊伸展到溶劑中，然後再將薄膜轉移到互溶性較差的溶劑acetone中使造成相分離)使聚胜肽分子的α螺旋一致性的向上垂直於基板表面。利用AFM原子力顯微鏡導電模式測量得之 I-V曲線，顯示出良好排列且垂直於表面的聚胜肽結構其整流效應足以用於在二極體的應用之上。

In this thesis, we use the effective synthetic approach (Surface-initiated vapor deposition-polymerization (SI-VDP)) to fabricate surface-grafted polypeptides on silicon, quartz, and Au surface for further applications. Firstly, biomimetic porous silica films have been synthesized by polycondensation of tetraethoxysilane on a soft template formed by “end-tethered poly(L-lysine)” (“t-PLL”) monolayer with a brush-like configuration. The silica formation occurs spontaneously inside the t-PLL at neutral pH and room temperature. The growth of silica fully conforms to the original t-PLL film thicknesses and lateral micro-patterns, regardless of prolonged reaction time and monomer concentration. The morphologies of biomimetic silica are changed from continuous pleated, discrete spherical, to fibrous forms according to the initial t-PLL chain length and surface density. After burning off the t-PLL template, TEM images show the creation of nano-channel arrays in silica with average diameter of 10 nm. Overall, our approach has provided a straightforward and environmentally friendly route to directly generate silica films with controllable morphology, thickness and porosity. Secondly, Polypeptide based molecular diode with high rectification ratio (~ 122 at ±0.422V) is formed by controlling molecular order and orientation. A film of tethered poly(γ-benzyl-L-glutamate) (PBLG) with high degree of molecular orientation was formed by solvent pair (good/bad) treatment. I-V characterization of the well aligned polypeptides showed that the rectification ratio of PBLG was sufficiently large for potential diode and transistor applications.