Combining Gold Nanoparticles with Antibody on SAM Modified Electrode for Trace Protein A Detection Based on Electrochemical Impedance Spectroscopy

• Main Authors: Chien-hao Huang, 黃建豪
• Other Authors: Hsien-Chang Chang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/89836284979930727045

碩士 === 國立成功大學 === 醫學工程研究所碩博士班 === 95 === The variation in concentration or the change of the structure of some special proteins related with diseases, which existing in the blood had passed for an important index of the development of diseases. Immunoassay, the measurement of antibody or antigen concentrations based on biospecific recognition interactions, has been considered as a major analytical method in the fields of clinic diagnostics and environmental analysis. It has been commonly used for detection of a variety of antigens and antibodies. Basically, it is sensitive (around 1-10 ng/ml) and specific. But the shortcoming of current immune analytical instrument is high price, narrow test project, convoluted operation. We try to develop an electrochemical impedance immunosensor to shorten the detection time and improve the detection limits of the target antigens. We used colloidal gold to enhance the amount of antibody immobilized on a gold electrode and ultimately monitored the interaction of antigen-antibody by impedance measurement. We used a novel amplification procedure with the application of an Au-colloid labeled antibody and special molecule as the amplifying probe. As a result, it showed that the detection of limit could reach to 5-1000 pg/ml of antigen concentration and higher than the traditional method in sensitivity. In summary, EIS provides good linear range to detection of antigen-antibody complex. To develop biosensing technique, impedance analysis and experimental parameter could be applied to detection of other affinity biosample.