Development of Amperometric Sensing Techniques for Biomolecules

• Main Authors: Shin Lin, 林鑫
• Other Authors: Tse-Chuan Chou
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/40114020305028394467

博士 === 國立成功大學 === 化學工程學系碩博士班 === 93 === 　The amperometric techniques for sensing the bio-molecules including the neurotransmitter, acetylcholine, and the marker of the inflammatory response, C-reactive protein (CRP), were developed. The sensing systems were including the homogeneous phase that the analyte was dissolved in the solution, and the heterogeneous phase that the analyte was adsorbed selectively on the chip, binding with the horse radish peroxidase for scanning electrochemical microscopy (SECM) sensing. 　The Ni(OH)2/NiOOH catalyst system was generated from Nickel wire and the electrochemical deposition Ni for sensing acetylcholine. The surface analysis of the Ni modified electrode was carried out by SEM and atomic force microscopy. The Ni deposited surface by high reduction current density resulted in the smoother morphology and better sensing performance for acetylcholine. The relation ship between the response current (y) and acetylcholine concentrations (x) was linearity according to limiting current equation. The sensing performance in the optima conditions obtained the calibration curves for Ni wire, y=0.095x+0.196, and for Ni modified electrode, y=0.187x-1.476. 　The assay for C-reactive protein was using antibody to fix C-reactive protein on the chip, binding the enzyme to generate the current response. The kinetic analysis of the SECM system contented the variables including the CRP concentration, tip applied potential, and tip sensing area. The CRP adsorption kinetic was analyzed by SECM, and the time to adsorption equilibrium was 60 minutes. The CRP detection limit was 0.1 µg/mL by using SECM-ELISA system. The relation ship between response current and the CRP concentrations was good linearity in the 0.1∼100 µg/mL CRP concentration region. The chip was approached the adsorption saturated when the CRP concentration was higher than 100 µg/mL.