Summary: | 碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 107 === This work is to develop an electrochemical biosensor immobilized with a selected peptide sequence. We demonstrated the electrochemical biosensor system using a selected peptide probe for Calmodium (CaM) detection and this peptide sequence (YWDKIKDFIGG) was obtained from in vitro ribosome display selection. In order to immobilized this peptide probe on the electrode surface, an amino acid containing thiol group was used as the end of this peptide sequence. A maleimide-functionalized poly(3,4-ethylenedioxythiophene), poly(EODT-MI), film was coated on the electrode surface and then immobilization of the peptide probe was achieved through thiol-ene conjugation. The charged amino acid in the peptide probe also provided an antifouling effect to non-specific protein binding. We used a quartz crystal microbalance to demonstrate the bioconjugation of peptide probe and evaluated the antifouling effect of this immobilized peptide probe against proteins. In electrochemical impedance analysis, the increase of charge transfer resistance after peptide immobilization and protein binding was also measured and quantitatively analyzed. The linear detection range for CaM is from100 ngL-1 to 10 mgL-1. Based on our results, this platform provides good sensitivity and a low detection limit. We plan to further apply this electrochemical biosensing system to other proteins, such as C-reactive proteins (CRPs).
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