藉由原子轉移自由基聚合反應將聚異丙基丙烯醯胺(poly N-isopropyl acryl amide, PNIPAAM)高分子刷接枝於矽晶片表面。晶片表面經過氧電漿處理後可增加表面氫氧基的含量，而表面的氫氧基可與3-aminopropyltriethoxy silane(APTES)反應，接著用α-Bromoisobutyl bromide與接枝上表面的APTES反應，以作為表面接枝高分子的起始端，藉由原子轉移自由基聚合反應(atom transfer radical polymerization, ATRP)可合成PNIPAAM高分子刷於矽晶片表面。X光光電子能譜(X-Ray photoelectron Spectroscopy，XPS)用於分析表面自組裝起始端以及PNIPAAM高分子之表面元素，使用橢圓測厚儀(Ellipisometer)量測PNIPAAM高分子刷厚度，而 PNIPAAM高分子刷在經過2小時的高分子聚合其厚度達到71nm，並使用原子力顯微鏡AFM(atomic force microscope)分析表面狀態。AFM影像顯示出在30-120分鐘聚合時間下之表面形態，在120分鐘的接枝時間均方根粗糙度為5.2537nm。

由由接觸角的量測，由接觸角60o變化80o，我們可以明顯的觀察到調控的親水疏水性質變化。我們證實了在反覆的低臨界濃度溶解溫度(Lower Critical Solution Temperature, LCST)循環測試下，證明其PNIPAAM高分子刷之可靠度。

利用PNIPAAM高分子刷之親疏水轉換機制，藉由聚合酵素連鎖反應(Polymerase Chain Reaction ，PCR)以及凝膠電泳(Gel electrophoresis研究人體血液染色體的去氧核醣核酸(Human blood genomic DNA)抓取釋放實驗，

實驗觀察指出，PNIPAAM高分子刷會在LCST溫度以下抓取50ng/ul 以及133ng/ul的特定DNA分子，在LCST溫度以上釋放出DNA分子。由結果得知，可以利用在矽晶片基材上面成長的PNIPAAM高分子刷作為一種新的特定DNA的萃取方式。

The poly (N-isopropylacrylamide) (PNIPAAm) brushes were grafted on the silicon surface by using atom transfer radical polymerization (ATRP). The silicon wafer surface was treated by oxygen plasma to increase the hydroxyl groups. The hydroxyl group on the surface reacted with 3-aminopropyltriethoxy silane (APTES), then α-Bromoisobutyl bromide was used to reacted with APTES to form the initiator of grafting polymerization on the surface. The PNIPAAm brushes was then synthesized on the surface through ATRP. The X-Ray photoelectron Spectroscopy（XPS） was utilized to analyze the surface element of SAMs of initiator and PNIPAAm brushes. The thickness of the PNIPAAm brushes on the surface was about 71 nm for 2 hours of polymerization time from mensurement by ellipisometer. The morphology of PNIPAAM was investigated by atomic forece microscope (AFM). AFM images show the morphology of the PNIPAAM brushes in 30-120 minutes polymerization, and The Root Mean Square roughness of PNIPAAM brushes in 120 polymerization time was 5.2537nm.

The surface with PNIPAAm brushes demonstrated obvious variations of hydrophobic and hydrophilic properties in contact angle measurement from 60o to 80o. We verify the reliability of PNIPAAm brushes through the 3 of the LCST cycle tests.

According to the hydrophobic and hydrophilic properties of PNIPAAM brushes, the capture-release application for human blood genomic DNA was investigated by Polymerase Chain Reaction(PCR) and Gel electrophoresis.

The observation suggests that the PNIPAAM brushes captured the human specific DNA form 50ng/ul and 133ng/ul of solution as the temperature below LCST. And the DNA was released as the temperature above LCST. The results demonstrated the new strategy for extraction for specific DNA by PNIPAAM brushes on the silicon substrate.

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