- 學位論文
以血紅素修飾電極發展亞硝酸根生物感測器
Development of nitrite biosensors based on hemoglobin modified electrodes
摘要
我們已完成一電化學式亞硝酸根生物感測器。該感測器之工作電極為石墨，以循環伏安法將聚苯胺電聚合於石墨電極表面，再以滴覆方式將血紅素覆蓋於修飾有聚苯胺之電極表面，再運用選擇性半滲透膜，如硫醇基丙基三甲氧基矽烷(3-mercaptopropyl trimethoxysiliane, MPTMS)包覆於電極最外層，藉此固定血紅素並排除干擾物質訊號之用。所完成之電極以安培法量測亞硝酸鈉與干擾物質之反應訊號，結果顯示，干擾物質之訊號都遠小於亞硝酸鈉的訊號。感測電極在室溫下之最佳操作電位為 +0.8 V；它對亞硝酸鈉濃度之偵測線性範圍為2 ~ 1000 µM(R = 0.9967)，偵測極限為1.59 µM(S/N = 3)。電極重覆製作5次，每次完成之電極用以量測22 µM亞硝酸鈉，所獲得之相對標準偏差為2.66 %，顯示電極製作步驟具有良好的再現性。當電極保存於室溫下之PBS溶液中一個月，期間所量測的訊號均維持在77.3 %以上，顯示此亞硝酸根感測電極具有良好之穩定性。
並列摘要
We have developed a hemoglobin (Hb) modified nitrite biosensor. In the fabrication, poly-aniline (PANI) was first electro-deposited on a graphite electrode (GPE). Hb was then added on the surface of the PANI modified electrode. Lastly, (3-mercaptopropyl) trimethoxysilane (MPTMS) was coated as the outmost layer of the electrode. This biosensor (MPTMS/Hb/PANI/GPE) was examined by amperometric measurements of sodium nitrite and interference substances of KNO3, Vitamin B1 and Vitamin C. The results show that the response currents from the interference substances were much less than that from sodium nitrite. When the measurements of NaNO2 was operated at the potential of +0.8 V (25oC), the linear response range of the biosensor is from 2 to 1000 µM with a correlation coefficient of 0.9967. The detection limit was estimated to be 1.59 µM at a signal to noise of 3. In the fabrication reproducibility study, five electrodes were used to independently measure 22-µM sodium nitrite. The compiled response currents show a relative standard deviation of 2.66% implying that the biosensor fabrication reproducibility is very good. This biosensor was stored in a PBS solution at room temperature for a month. Within this period of time, all measured signals remained above 77.3% comparing to that measured at the very first day showing that it possessed good stability.