A New Fluorescence Immunosensing Method Based on Aptamer-plasmid Complex Amplification / 分析化学

ABSTRACT

A novel simple,sensitive fluorescence immunosensing method based on aptamer-plasmid complex amplification was developed. This method utilized the specific recognition between antibody and antigen as well as aptamer-plasmid complex and the intercalation of fluorescence dye SYBR Green Ⅰ in the groove of duplex plasmid DNA in detection of Platelet-Derived Growth Factor BB (PDGF-BB). The immunoassay was performed in the microtiter wells in which rabbit anti PDGF-BB antibody was immobilized. The PDGF BB analyte was captured by the primary antibody and then sandwiched by the aptamer-plasmid DNA complex. The introduction of fluorescence dye SYBR Green Ⅰ allows for the detection of the sandwiched immunocomplex of antibody/anigen/aptamer-plasmid complex. Under the optimized conditions of salt concentration,ratio of aptamer to PUC19,and SYBR Green Ⅰ concentration,the proposed method offers a linear detection range from 0.2 μg/L to 200 μg/L with a detection limit of 0.1μg/L.