gold nanoparticles modified self-doping polyaniline electrode for signal enhancement of electrochemical immunosensors

• Main Authors: Sheng-Yu Huang, 黃聖祐
• Other Authors: Yung-Chuan Liu
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/tn953p

碩士 === 國立中興大學 === 化學工程學系所 === 100 === A competitive immunosensor, based on the indium tin oxide(ITO) electrode modified by self-doping polyaniline(SPAN), was fabricated for the detection of human serum albumin(HSA) by measuring the differential pulse voltammograms(DPV). Compared to other immunosensors applying electrodes modified by conducting polymer, this study o-aminobenzenesulfonic acid(SAN) dopped Aniline(AN) to make the morphology of AN in the form of microsphere, resulting in the boost of signal, the extension of detection range, and the sustainability of high conductivity, high biocompatibility and high stability of AN due to high surface area of microsphere. In this study, a competitive binding of antigen in samples or on test line to antibody was adopted as the principle to indirectly determine the concentration of antigen in samples. In addition, secondary antibodies(goat anti-mouse) coupled with colloidal gold were used as the marker to amplify the signal of immunosensors. The concentration of the immobilized HSA, the highest concentration of anti-HSA and the concentration of secondary antibody conjugated with colloidal gold were found as follows: 250 μg/mL, 20 μg/mL, 5 μg/mL. The linear range was from 10 to 200 μg / mL with a optimal detection limit of 1μg/mL. After adding colloidal gold particles to amplify the signal, the linear range was from 0.5 to 200 μg/ml with a detection limit of 413 ng/ml. The proposed competitive immunosensor is easy to prepare, with the advantages of low-cost, wide linear detection range and good signal response. This assay provides a clinical testing method for measuring human serum albumin concentrations via single-use competitive immunosensor of ITO electrode modified by SPAN.