在本研究當中利用電化學與表面電漿共振技術來偵測人體血清白蛋白受鉻(VI)後導致構形的改變，本研究採用載玻片濺鍍47nm金膜，以自我聚集方式(Self-assemble monolayer)吸附二胺基硫代乙醇(2-aminoethanethiol)，再吸附人體血清白蛋白(HSA)後作為偵測電極，再將含有鉻(VI)溶液流過吸附HSA的電極，利用電化學與表面電漿共振技術能即時偵測的優點，來偵測人體血清白蛋白在受鉻吸附後所產生的構形變化，在表面電漿共振技術方面，利用人體血清蛋白(HSA)在含鉻(VI)溶液中產生的共振角偏移，判斷人體血清白蛋白之構形變化程度。在電化學技術方面利用以下三種:1.比較此系統開路電壓OCP之高低以判斷人體血清蛋白遭受鉻中毒之構形改變程度。2.另外，CV圖譜中（電流對電壓圖）藉由電流訊號的改變會影響電壓之測量，電壓峰值出現位置及振幅高低，顯示人體血清白蛋白受鉻毒害後之構形改變大小。3.交流阻抗頻譜法可用來探討電化學系統電容、電阻等。由人體血清白蛋白(HSA)與鉻(VI)反應前後電容、電阻等變化，量測此與蛋白質構形改變之關聯性。除了即時偵測人體血清白蛋白與鉻所造成的構形變化外，也分析表面電漿共振與電化學數據的正確性與靈敏度提升。在表面分析方面則以原子力顯微鏡(AFM)探測蛋白質遭鉻離子(VI)毒化前後表面之粗糙度變化。FT-IR光譜儀則用於檢測蛋白質在遭鉻(VI)離子構形改變前後之鍵結震動模式變化。 The conformational change in human serum albumin (HSA) has been investigated using dc-cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and surface plasmon resonance (SPR) technique in this work. A slice of glass was sputtered a thin film of gold (47 nm), undergone self-assembly of 2-aminoethanethiol (AET) in ethanol solution and coated with the HAS solution to act as a specimen for this study. A stream of dichromate (Cr2O72-) solution flowed on the immobilized HAS caused a bio-interaction between the HAS and Cr (VI) thus resulting conformational change of the HAS. SPR and electrochemical techniques were used in the following to monitor the in-situ conformational change of the HAS due to its bio-interaction with Cr (VI).1. Monitoring using SPR technique: The interfacial change resulted from conformational change of immobilized HAS caused by Cr (VI) could be detected using SPR through the change of resonance angle.2. Monitoring using electrochemical techniques: (1) Shift in the open circuit potential (OCP) of the system reflected the conformational change of the HAS resulted from its toxic reaction with Cr (VI) ion. (2) Presence of current peaks in cyclic voltammograms (CV) at certain potentials were responsible for specific toxic reactions between the HAS and Cr (VI) ion. (3) Analysis of the resistive and capacitive data of the EIS provided a check on the conformational change of the HAS arisen from its toxic reaction with Cr (VI) ion. In additional to monitor the toxic reaction between the HAS and the hexavalent chromium. The validity and sensitivity of the SPR and electrochemical signals are discussed. The surface roughness of the system was estimated by atomic force microscope (AFM). The conformational change of the HAS was confirmed via analysis of vibration mode from the FT-IR spectroscopy.
