To develop new technology for detecting methicillin-resistant Staphylococcus aureus (MRSA), a novel fluorescent biosensor based on Klenow fragment (KF)-assisted target recycling amplification and synchronous fluorescence analysis was created. Carboxy-fluorescein (FAM)-labeled single-stranded DNA (ssDNA) containing a capture probe and a signal probe was adsorbed onto the surface of graphene oxide (GO) via π-stacking interactions, resulting in the fluorescence quenching of the dye. When target and primer were introduced, the fluorescence was res...