In this work, we report the design of a new multi-functional, water-soluble conjugated polymer integrating both a DNA intercalator and a redox label. Based on this multi-functional conjugated polymer, we develop a sequence-specific electrochemical DNA sensor, where the acridine unit serves as the basis for sequence discrimination, and the ferrocene label provides the electrochemical signal. Moreover, the conjugated polythiophene helps transfer electrons from ferrocene to the electrode. This sensor provides a new way for rapid and convenient detection of DNA targets.