心血管疾病(CVD)為世界上致死率最高的疾病，若能早期發現並投以治療
能夠降低心血管疾病病患的死亡率。現今的心血管疾病診斷大多仰賴醫療院所
的大型設備進行血液中生物標記物檢測，這種檢測方法通常耗時且步驟繁複。
過去幾年，本研究團隊開發出一種能在5 分鐘內檢測血液中蛋白質的生醫感測
器。這種電雙層閘極門控場效電晶體生醫感測器具有高靈敏度、寬動態檢測範
圍並且能在生理鹽濃度下進行蛋白質檢測。過去，我們致力於研發感測器，現
在我們著力於研究其感測機制以便我們優化、提升感測器之性能。
　　在此研究中，我們首先以我們開發的感測器在 1X PBS 緩衝液中感測
CRP，並改變閘極偏壓來研究蛋白質感測器的表現和機制，並加入阻抗分析來
證實我們所提出的感測機制。感測器在不同閘極偏壓下的汲極電流將被汲取並
轉換為溶液中壓降加以分析，並藉由改變測試樣品離子強度來觀察感測器靈敏
度的變化以證實感測器的電雙層理論。
　　為達到居家照護的目標，感測晶片的保存技術的開發是必要的。我們針對
蛋白質感測晶片的保存進行研究，尋找適合的試劑配方來乾燥抗體功能化的感
測晶片以達到長期保存的目標。

Cardiovascular disease (CVD) is one of the deadliest diseases in the world. Early detection and treatment can reduce mortality in patients with cardiovascular disease. Currently, the technology of CVD biomarker detection relies on large equipment and it is expensive, inconvenient and time consuming. A technology for protein biomarker detection in the whole blood within 5 minutes has been developed. This electric double layer (EDL) field-effect transistor (FET) gated biosensor has high sensitivity, wide dynamic detection range and can carry out protein detection at physiological salt concentration. In this study, we focus on the mechanisms of this technology. The gate voltage bias (Vg) and the ionic strength of testing sample were changed to study the effect on sensor performance. And the AC impedance analysis was introduced to demonstrate the sensing mechanism we proposed. To realize the goal of point-of-care, the development of chip storage technology is necessary. The drying process of the antibody-immobilized sensor chip for long term storage was developed by looking for appropriate protectant formulations.

Chapter 1. Introduction 5
Chapter 2. Literature Review 8
2.1 FET based biosensor 8
2.2 Electrical double layer (EDL) and charge screening effect 10
2.3 Electrical double layer (EDL) FET biosensor 12
2.4 Sugar as protectant for antibody drying process 14
Chapter 3. Experimental 16
3.1 Fabrication of extended gate sensor chip 16
3.2 Surface functionalization for extended gate sensor chip 17
3.2.1 Conjugating by primary amine group 18
3.2.2 Conjugating by carboxyl group 19
3.3 Measurement system 20
3.3.1 Portable circuit device 20
3.3.2 Impedance analysis 22
Chapter 4. Results and Discussion 23
4.1 Characteristic of MOSFET in circuit device 23
4.2 Protein detection at different gate voltage 25
4.2.1 Detection with EDL FET gated biosensor 25
4.2.2 Impedance analysis for protein detection 29
4.3 Protein detection in different ionic strength solutions 32
4.4 Mechanism of EDL FET gated biosensors 41
4.5 Drying process of antibody-functionalized sensor chip 44
Chapter 5. Summary and Future Work 48
Chapter 6. Reference 50

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