A Modified Gold Electrode for a Portable Alpha-fetoprotein (AFP) Bio-sensor

• Main Authors: Yu-Ling Chang, 張郁苓
• Other Authors: Fuh-Sheng Shieu
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/77734947664082901392

碩士 === 國立中興大學 === 材料科學與工程學系所 === 104 === We directly detect AFP (alpha-feto protein) with only anti-AFP immobilized with thiolated compounds to gold electrode sensor, with electrochemical analysis data to quantify the concentration levels of AFP in the phosphate buffer solution. After cleaning three-electrode sensor with alcohol and D.I. water, the electrode was immersed in the freshly prepared solution with certain ratio of co-assembling thiolated molecules of dithiothreitol (DTT) and 3-mercaptopropionic acid (3-MPA). With the property of specific affinity for combination of antibody and antigen, this chemical modified sensor could be used to detect antigen, AFP, without enzyme, dyes or sandwich-assay design. For electrochemical analysis, the additional antigen was involved to form antibody-antigen complex which contributed to the signal of current. In our interested potential, 0.2 V (vs. Ag/AgCl), the correlated current was noted to form the calibration curve for all the comparisons. Overlapping the differential pulse voltammetry of several concentrations, 0.01 ng/μl was successfully detected with a 1:20 DTT/thiol ratio. Addition of DTT to make a non-fouling surface did enhance the sensitivity of antibody-based AFP biosensor.