High levels of performance and stability have been demonstrated for conjugated polymer thin-film transistors in recent years making them promising materials for flexible electronic circuits and displays. For sensing applica-tions, however, most research efforts have been focusing on electrochemical sensing devices. Here we demonstrate a highly stable bio-sensing platform using polymer transistors based on the dual-gate mechanism. In this architec-ture a sensing signal is transduced and amplified by the capacitive coupling between a low-k bottom-dielectric and a high-k ionic elastomer top-dielectric that is in contact with an analyte solution. The new design exhibits a high signal amplification, high stability under bias-stress in various aqueous environments and low signal drift. Our platform furthermore, while responding expectedly to charged analytes such as the protein BSA, is insensitive to changes of salt concentration of the analyte solution. These features make this platform a potentially suitable tool for a variety of biosensing applications.