標題: 功能性磁奈米複合材料輔助電化學偵測多巴胺
Functional magnetic nanocomposite assisted electrochemical detection of dopamine
作者: 洪文熙
謝有容
應用化學系碩博士班
關鍵字: 四氧化三鐵磁性奈米粒子;磁奈米複合材料;4-硫氫基苯硼酸;多巴胺;Fe3O4;magnetic nanocomposites;4-mercaptophenylboronic acid;dopamine
公開日期: 2011
摘要: 四氧化三鐵磁性奈米粒子 (Fe3O4 magnetic nanoparticles,Fe3O4 MNPs) 具有超順磁性,能夠經由外加磁場的方式簡單操作,且生物毒性低,目前已被廣泛應用於各種生醫用途上。而在表面包覆上金奈米粒子後所形成的磁奈米複合材料 (magnetic nanocomposite),結合了磁奈米粒子具有良好的磁性和可以利用外加磁場而輕易操作,以及金奈米粒子具有容易修飾和高生物相容性之特性,可應用於多種包含電化學偵測等不同領域。 利用 4-硫氫基苯硼酸 (4-mercaptophenylboronic acid,4-MPBA) 對於多巴胺 (dopamine) 具有高度選擇性為基礎,藉由表面以金奈米包覆的四氧化三鐵磁奈米粒子 (gold nanoparticles coated Fe3O4 magnetic nanoparticles,Au@MNPs) 做為載體,將 4-MPBA 利用其結構中之硫醇官能基,以硫 - 金鍵結的方式修飾於複合磁奈米表面而形成功能性磁奈米複合材料 (functional magnetic nanocomposite)。 修飾於磁奈米複合材料上的 4-硫氫基苯硼酸,與水溶液中的多巴胺進行酯化反應後,經由外加磁場於工作電極的方式,使磁奈米複合材料聚集至電極表面,大幅度的濃縮了散佈於溶液中的多巴胺而達成預濃縮的功用,進而提升偵測靈敏度以及降低偵測極限。濃縮於電極表面之多巴胺,在偵測氰化鐵/氰化亞鐵錯合物時會形成屏蔽作用而降低得到的電流訊號,藉由比較電流差值,即可間接定量多巴胺的濃度。 經由4-硫氫基苯硼酸修飾磁奈米複合材料,並與電化學結合進行預濃縮線上偵測的方式,發展出了對於偵測溶液中的多巴胺具有高靈敏度以及良好選擇性的分析方法,偵測極限為 1.6 pM (S/N = 3),線性範圍則在 10 pM 到 1 μM之間 (R2 = 0.9935)。並且對於未來應用於生物感測的研究方面,也有許多的發展空間。
Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) existing super paramagnetic characteristic and can be easily manipulated by external magnetic field. After coating with gold shell, the functional magnetic composites can be widely used in biochemical or clinical related researches. Based on the specific interaction between 4-mercaptophenylboronic acid (4-MPBA) and dopamine, the functional magnetic composites were decorated with 4-MPBA on the surface via Au-S self-assembly mechanism to capture dopamine in the sample solution. By applying magnetic field, the dopamine in the sample solution which captured by magnetic nanocomposites can be gathered to the surface of the electrode. This procedure concentrated the analyte at the electrode surface, which enhanced the sensitivity of the measurement. The developed method had high sensitivity and good selectivity detecting dopamine. The linear range was from 10 pM to 1 μM with R2 equal to 0.9935 and the estimated limit of detection (LOD) was 0.16 pM (S/N = 3). The proposed method improved the sensitivity of detection and can be further applied to different biosensors or bioelectronics devices in various fields.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT079825550
http://hdl.handle.net/11536/47638
Appears in Collections:Thesis