摘要
膽固醇是構成細胞膜的主要成份，亦是合成固醇類荷爾蒙的前驅因子；血液中膽固醇的量不正常是脂質代謝失調的指標，而其在粥狀動脈硬化、高血壓等病因及病程中亦扮演著重要的角色，故膽固醇檢測方法成為臨床檢測中重要的課題。 本論文係研究以酵素固定化製程結合延伸式閘極感測場效電晶體之膽固醇生醫感測器。研究中採用延伸式閘極感測場效電晶體進行pH值變化之偵測，其感測膜的備製，係利用射頻濺鍍機將二氧化錫沈積在ITO玻璃基材上；在實驗中，我們嘗試二種不同生化辨識元件，包括膽固醇酯@及膽固醇去氫@，並利用酵素固定化技術，分別以架橋連結及膠體包埋的方式製作酵素延伸式感測場效電晶體，其中待測液係利用200mg/dL膽固醇標準液以磷酸鹽緩衝液稀釋備製。 依據實驗結果顯示，固定膽固醇酯@之感測器無法測得脂肪酸濃度之變化，但以膽固醇去氫@取代膽固醇酯@後，則產生明顯之電壓變化，而以膠體包埋的方式固定酵素膜，其線性度及穩定度均較架橋連結的方式佳；配合輔@用量及其與膽固醇去氫@的作用時間，可調整感測器之電壓響應值及反應時間。此膽固醇生醫感測器具有微小化、可拋棄式之優點，可對低濃度之膽固醇進行線性檢量，其線性範圍在濃度20～160mg/dL之間。
並列摘要
Cholesterol is one of the major constituents of cellular membranes and is a critical precursor molecule for the synthesis of steroid hormones. It can play a critical role in a person’s health because atypical total cholesterol in serum is an indicator of the abnormality in the lipid metabolism, of arteriosclerosis and hypertension. It’s improtant that all people know what their cholesterol level is and how it affects their risk of developing heart disease. In this thesis, we develop the cholesterol biosensor by the enzymatic immobilization connecting with the extended gate field effect transistor (EGFET). In this study, we use the EGFET to detect the variation of pH value. The sensing layer was obtained by depositing SnO2 on the conductive ITO glass with the sputtering method. We choose two different biological recognition devices, including the cholesteryl ester hydrolase (CEH) and cholesterol dehydrogenase (CDH). Then we make use of the enzymatic immobilizing technology, including the cross-linking and gel entrapment, to manufacture the enzyme modified field effect transistor (EnFET). The sample solution was prepared by diluting the 200mg/dL cholesterol standard. The results show that CDH EnFET has much more obvious variation than CEH EnFET which can’t detect the variation of the fatty acid. And the linearity and the stability of the EnFET using gel entrapment technology are better than that of using cross-linking technology. The output voltage and response time could be adjusted by changing the quantity of co-enzyme or the incubating time of CDH and co-enzyme. The cholesterol biosensor has advantages of the minimization and disposability. The cholesterol biosensor can detect cholesterol of lower concentration and its linear range is between 20 and 160mg/dL.