DNA(去氧核醣核酸)是掌管生物體中遺傳訊息的重要物質，而DNA檢驗的技術也廣泛被應用在生醫相關領域上。與螢光標定法相比，利用DNA本身電性所開發出的電性感測系統可以在相對較低的成本及技術需求下完成DNA即時檢測的工作。然而，DNA電性檢測系統之靈敏度與解析度受限於反應環境、DNA感測元件特性、電路架構等因素，無法達到實務應用的需求。若能改善以上問題，則可以省去DNA檢測前所需的化學反應，進而達到實務上應用的可能。
本論文嘗試利用各種不同的手法提升DNA電性檢測系統的靈敏度。於本論文中，一版電荷感測電路以及一版阻抗感測電路被設計以感測水溶液中之DNA含量。於感測電路中，本論文使用經過親水性處理之金電極EGFET增強DNA訊號，同時利用內部雜訊較低的感測電路降低其對靈敏度的限制。此外，由於DNA感測元件之靈敏度為決定整體系統靈敏度之最大要素，本論文嘗試利用台積電90奈米標準製成製作奈米線元件，並嵌入於感測晶片內，藉此達到較高之解析度及解析度，同時設計一版導電度感測電路以測量奈米線元件導電度之變化。
量測及實驗結果顯示本次設計之兩版電路皆可量測到DNA反應所產生的訊號，而DNA反應之訊號之大小與EGFET表面電極之大小有關。奈米線元件之量測部分由於結構問題並無法表現正確的特性，而感測電路部分以電阻取代奈米線元件進行量測，量測結果顯示導電度感測電路則可以偵測到元件之導電度變化。

DNA sequences store the genetic information of creatures, and DNA detection technique is employed for biochemical applications. Compared with fluorescent labeling, the detection system based on electrical characteristic of DNA can achieve DNA detection utility with lower cost and lower technical requirement. However, the sensitivity and the resolution of DNA detection system are restricted by the reaction environment, the characteristic of sensing devices, and the structure of readout circuits. If these issues can be solved, the chemical treatment before DNA detection can be omitted to reach practical application.
Different DNA detection mechanism is employed in this thesis to improve the sensitivity of an electrical DNA detection system. In this thesis, a charge detection circuit and an impedance detection circuit is designed to sense DNA concentration in a solution. A gold electrode EGFETs with hydrophilic treatment are employed in this thesis to enhance the DNA signal, and the low-noise detection circuits are employed to improve the sensitivity of the detection system. Moreover, since the sensitivity of DNA sensing device dominates the performance of the detection system, a nanowire device made in TSMC 90nm process is designed and embedded in sensor chip to reach higher sensitivity and resolution. A conductance detection circuit is design with the nanowire to detect the conductance change of nanowire.
The measurement results and experiment results show that both charge detection circuit and impedance detection circuits can detect signals of DNA reaction. The size of gold electrodes affects the amplitude of DNA signals. The electrical characteristic of

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