Novel adenosine detection method based on cationic conjugated polymer and aptamer

We designed a novel adenosine detection system based on cationic conjugated polymer(CCP) and aptamer. A fluorescein-modified short-chain DNA can partially hybridize with adenosine aptamer to form a double stand DNA(dsDNA). The CCP associated with the dsDNA by electrostatic attractions and an efficient fluorescence resonance energy transfer(FRET) from the CCP to the fluorescein occurred. When adenosine was added, it bonded specifically to the aptamer, making the dsDNA break into single stand DNA(ssDNA), then the FRET efficiency decreased. Thus, we could detect the adenosine quickly and easily through the high signal discrimination between dsDNA and ssDNA with the CCP. The results show that the degree of FRET efficiency decrease is related to the concentration of adenosine. This detection method has the advantages including easy operations, low costs, and relatively high sensitivity; moreover, it can be extended to detections of other targets owning aptamers.