利用生物有機場效電晶體應用於生物檢測訊號之研究

Abstract

近年來由於個人健康醫療之市場需求日益增加，迫使生物感測領域在性能與商業性上不斷精益求精，開發出多種型態之新型生物感測器，而其中電晶體生物感測器(NWFET、CNT FET)之精準度與便利性使其被賦予高度之觀注，然而其高成本之特性卻成為商業化之阻礙，反觀於此，電化學式生物感測器因發展歷史久遠，技術純熟，具有訊號輸出穩定與成本低廉兩大特性，使其在商業市場上屹立不搖，有鑑於此，若能將電晶體生物感測器與電化學生物感測器結合，將兩者之優點結合於一新型之結構，勢必能夠為未來之生物感測器開發上提供新的衝擊，因此，本論文首度提出以生物層搭配高導電性之定錨材料成為電晶體之半導體材料材，建構出新型之生物場效電晶體結構，並利用半導體特性分析儀做為量測之儀器，所使用之生物分子為甲型胎兒蛋白(AFP)與S100，在兩種不同之生物樣本中，皆能觀察到施加閘極電壓可達到電流差異放大之現象，其放大比例最高可達二倍，而在S100 濃度測試中亦成功以施加閘極電壓(-20V)將元件之精準度由無施加閘極電壓的無法偵測情形大幅提升至1μg/mL，更加確認施加閘極電壓的確可以造成電流差異(current difference)的放大，並透過BSA 分子進行專一性測試，確定經由本論文之晶片設計可成功偵測專一性之反應，因此，在本論文中之先期研究可成功確立此結構之可行性。

In recent year, the requirements of the personal healthcare are rsing significantly.Beacuse of the urgent requirements on the market, the researches of low-cost disaposable bio-sensors are one of the major topic in the filed. Researchers suggest many new types of bio-snesor to people, and among of the all, the field-effect-transistor(NWFET、CNT FET) gets the lots of attention because of its high sensitivity and ease of use properties. However, higher cost limited the widely commercial use of theses types of sensor. The most popular type of bio-sensor in personal healthcare is electrochemical biosensors because of its stablity and relatively lower cost. If we can combine the advantages of two types of biosensors as a new type biosensor, the new type of sensor will be most competitive and has potential in commercial market. From this viewpoint, we proposed a new type of biosensor mechanism which combines the structures of the two types of biosensors and will be verified in this thesis. We use the bio-material (AFP and S100) and the high conductive linker (CT5) to be the semiconductor layer of our bio-organic field effect transitor. We found the structure constructed by two materials can truly have field effect. When applying gate voltage, Vg, -20V to the chip, we can get the current difference enlarged for two times at most, compared with pure electrochemical effect without the external electric field built-up by the applied gate voltage. In the concentration tests on S100 protein on the bio-organic field effect transitor with -20V Vg,the sensitivity of the sensor could rise from non-detectable to 1μg/mL. In the end, we use the BSA molecule to verify the specific binding effect. The measured current signal became much smaller than in the specific binding situation so as we can claim the strucute of this sensor can truly detect the specific binding and the sensitivity of the chip is achieve 1μg/mL.