能量消散型石英晶體微天平對於共價有機框架在水相環境中藥物客體吸脫附過程之研究

Abstract

共價有機框架（Covalent Organic Frameworks, COFs）為一種新型有機多孔材料，其有著結構清楚明確、可調性孔洞、比表面積大、穩定性高等特性，再加上碳、氧、氫、氮等輕元素之間具有穩固的強共價鍵，因而在能量儲存與轉換、光電元件、氣體分離、感應器、催化、藥物傳輸等領域有著廣泛的應用，在這些應用中，了解吸附和脫附的行為是COFs成功的關鍵。 本實驗採用界面聚合法將作為反應物的三甲醯間苯三酚（2,4,6-Triformylphloroglucinol, TFP）和三(4-胺基苯基)胺（Tris(4-aminophenyl)amine, TAPA）合成為β-酮烯胺（β-Ketoenamine-linked）連接的COF薄膜。利用掃描式電子顯微鏡（SEM）、原子力顯微鏡（AFM）、傅立葉轉換紅外線光譜儀（FTIR）、界面電位分析儀等方式對TAPA-TFP薄膜進行表徵，以了解其形貌、厚度、結構及界面電位。並利用能量消散型石英晶體微天平（QCM-D）的高質量靈敏度，連續記錄共振頻率和能量消散的變化，以研究小分子客體在不同pH值水溶液中的吸附與脫附行為。 將大約17.5 nm的獨立TAPA-TFP薄膜直接轉移到石英晶片上以形成穩定且均勻的塗層，選取磷酸鹽緩衝生理鹽水（Phosphate buffered saline, PBS）溶液作為本實驗的背景溶液，並分別通入酸性及鹼性的PBS溶液，得知TAPA-TFP薄膜在pH 6 – pH 3能有穩定結構，後續選擇咖啡因作為本次實驗的客體分子，將晶片暴露於含有咖啡因的緩衝溶液中，發現隨著pH值越小，QCM-D收取之資料變化顯示可逆的質量減少，結構會從通入藥物溶液後造成的鬆散再變得緻密，因而擠壓出咖啡因溶液。

Covalent organic frameworks (COFs) are a kind of emerging porous crystalline material, which have well-defined structure, tunable pore size, large specific surface area, high stability with robust covalent bonds between light elements of C, O, H, and N. As a result, they can be applied in energy storage and conversion, optoelectronics, gas separation, sensors, catalysis, drug delivery, etc. For these applications, the adsorption and desorption behaviors are key to their success. In this work, the β-ketoenamine-linked COF synthesized from 2,4,6-triformylphloroglucinol (TFP) and tris(4-aminophenyl)amine (TAPA) film was prepared with interfacial polymerization. The TFP-TAPA film was characterized by SEM, AFM, FTIR, Zeta Potential Analyzer to identify its morphology, thickness, structure and zeta potential. For its high weight sensitivity, quartz-crystal microbalance with dissipation detection (QCM-D) was used for investigating the adsorption and desorption behaviors of small molecular guests in aqueous solution of different pHs. Approximate 17.5 nm thick standalone TFP-TAPA film was transferred to quartz crystal chip directly to form a stable and uniform coating. Using phosphate buffered saline (PBS) as the blank buffer, and the film was exposed to acidic and alkaline PBS solutions respectively. It was found that TAPA-TFP film can have a stable structure between pH 6 to 3. Subsequently, the chip was exposed to a buffer solution containing caffeine between pH 6 to 3. It was found that as the pH value decreased, the data collected by QCM-D showed a reversible mass reduction. The result reflected the structure would change from loose to dense, and some of the caffeine solution was lose from the film.