有機薄膜電晶體生物化學感測研發

Abstract

本計劃將開發有機薄膜電晶體在生物感測上的應用，利用(1)有機薄膜(pentacene)結合生 物材料後對特定分子的專一性及選擇性、(2)小分子可經由有機薄膜晶粒邊界滲入到靠近 電晶體閘極介電層處進行吸附、以及(3)有機薄膜電晶體特有的介電層表面自我組織層 (Self-Assembled Monolayer，SAM)技術；讓我們可以有效的使用標準底閘極結構有機薄 膜電晶體來發展生物感測電子元件。在我們的初期研究中，已經成功觀察到尚未被發表 的新穎實驗結果，看到電晶體在不同氣體(酸性或鹼性)環境下，會呈現截然不同的電性 反應，此電性變化快速且強烈、又具有可回復性，相當適合進一步發展檢測具有大量胺 基及羧基的胺基酸複合物。因此本計劃提出系統化的研究方式，分兩年時間探討有機薄 膜電晶體在不同氣體環境下的反應機制、更發展帶有不同官能基的胺基酸SAM技術，分 析官能基對感測之影響；更利用合成的勝.分子同樣進行介電層表面固定化，檢測其官 能基組成對感測反應之影響、並建立感測之選擇性。由於防水剝除的有機薄膜電晶體已 經成功被提出，所以本研究成果未來可以順利轉移到液態微流道的生化感應中，預期可 固定高專一性的aptamer等核酸或勝.分子來進行更廣泛的生物感測；加以有機薄膜電晶 體低成本、易製作、可製作於可撓式基板形成感測陣列等優勢，以及此一新領域在國際 間仍亟待進一步闡述；相信本研究不管在產業或學術上，都極具價值。

Organic thin-film transistors (OTFTs) sensors use the organic semiconductor active layer as the transducer to interact with biochemical species. The absorbed biochemical analyte could affect charge transport in the channel by trapping charges. Though the sensing mechanism is not clearly understood, it was suggested to be a dielectic surface-type interaction involving grain boundaries. In our project, the mechanism of OTFT biosensing behavior will be studied systematically. Firstly we will use SAM(self-assemble monolayer) technology to immobilize amino acid, the surface energy of the dielectric will be modified. Amino acides with side chains such as aromatics, amines, or carboxylic acids, etc will be used to study the sensing behavior in environments with different gas moleculares. Then, we will analyze the sensing response associated with side chains and gas moleculars. OTFTs with 4-probe structure will be used to separate the influences of conducting film and the metal/organic interface. Finally, the synthetic peptides will be also immobilized onto OTFT dielectric surface. The sensing behavior under different combination of amino acid』s side chains will be analyzed. Further more, biosening by incorporating aptamers into OTFTs will be studied in future works.