Methods, compositions and articles of manufacture for assaying a sample for a target polynucleotide are provided. A sample suspected of containing the target polynucleotide is contacted with a polycationic multichromophore and a sensor PNA complementary to the target polynucleotide. A signaling chromophore absorbs energy from the excited multichromophore and emits light in the presence of the target polynucleotide. The methods can be used in multiplex form. Kits having reagents for performing such methods are also provided.