以化學拔除法選擇性組裝置放奈米粒子

Abstract

本研究使用化學拔除法建立圖形化的自組裝單分子層，並將其應用於奈米粒子在基材表面的自組裝。化學拔除法是一項製造高解析度單分子層圖形的技術，此方法不僅可以精準控制表面自組裝硫醇分子的位置，且經過處理的表面更會具有與以往不同的性質，進而影響奈米粒子的置放，例如：表面有胺基的奈米粒子置放在經過化學拔除的表面與未經處理的表面上之數量有相當大的差異。因此，本研究對基材表面的性質進行探討，透過這些性質的調控，會改變奈米粒子與基材間的表面化學吻合性，進而影響奈米粒子的置放結果。 此外，不同表面官能基的奈米粒子亦會對表面具有不同且高度的選擇性，例如：表面為羧基的奈米粒子會透過氫鍵作用力而吸附於末端為羥基的自組裝單分子修飾層上，但由於缺乏與金表面的親和性而無法置放在經過化學拔除的區域。另外，表面為胺基的奈米粒子會藉由氮金作用力而大量置放於經過化學拔除的區域，僅有少數的奈米粒子會因氫鍵作用力而吸附於修飾單分子層的表面。 結合製造高品質單分子層圖形以及改變表面性質的優點，本實驗更進一步將化學拔除法製作的單分子層圖形應用於奈米粒子的自組裝置放，並且成功製造出於微米與奈米尺寸下的奈米粒子排列圖形。

Nanoparticle patterning attracts considerable attention due to its wide application in many fields, such as bio/chemical sensors and electronics. However, close-packing nanoparticles at specific regions and deposition control with high fidelity still face many challenges. Herein, a strategy for high quality nanoparticle patterning by chemical lift-off lithography (CLL) is demonstrated. Chemical lift-off lithography is a promising technique to fabricate high resolution self-assembled monolayer (SAM) patterns on gold substrates. In this study, functionalized nanoparticles are selectively deposited into different areas created by the chemical lift-off processes, while the allocation of nanoparticles relies on their surface functionalities. It is found that amine-containing molecule functionalized nanoparticles tend to pack into the post-chemical lift-off regions, while the carboxyl-rich molecule encaptured ones preferentially sit at the hydroxyl‑terminated SAM covered areas. This strategy provides a straightforward way to selectively deposit nanoparticles with high fidelity and controllable density. Futhermore, high quality micro/nano scale nanoparticle packing patterns are achieved.