本研究乃利用量子點(quantum dots, QDs)獨特的發光特性,將其附著於奈米碳管(carbon nanotubes)表面,實現使用螢光顯微鏡觀察奈米碳管之目的。為達此一目的,本研究合成一具有mercapto group與pyrenyl group之雙官能基分子(bifunctional molecule),分子結構中之mercapto group可與殼層為ZnS核心為CdSe之量子點(CdSe/ZnS QDs)表層Zn原子產生鍵結,使CdSe/ZnS QDs具有pyrenyl group,pyrenyl group與奈米碳管管壁具有π-stacking非化學鍵結靜電力吸附。因此以雙官能基分子進行改質後之CdSe/ZnS QDs表面即具有pyrenyl group,因π-stacking現象存在而使CdSe/ZnS QDs可自組裝於奈米碳管管壁,利用CdSe/ZnS QDs受激發時放射之可見光,達到利用光學顯微鏡觀察奈米碳管之目的。本研究同時利用穿透式電子顯微鏡確認自我組裝於奈米碳管表面。
This work is to present a simple visualization technique for carbon nanotubes (CNTs) observation in fluorescent optical microscope. A noncovalent coupling approach is proposed to conjugate fluorescent ZnS-capped CdSe quantum dots (QDs) to unmodified single-walled/multi-walled CNTs (SWCNTs/MWCNTs) via a bifunctional molecule, 1-(1-pyrenyl)-1-methanethiol, which contains mercapto and pyrenyl group. The pyrenyl group can interact strongly with the sidewall of CNT via noncovalent π-stacking, and the mercapto group was bound to the Zn atoms of ZnS-capped CdSe QDs, forming QDs-CNT complex. The fluorescent QDs-CNT complex makes it possible to observe CNTs directly by using fluorescent optical microscope. The success of QDs self-assembly to CNT’s sidewall were further verified by transmission electron microscope (TEM)