a chemical composition including a moiety comprising a quencher , a tethering element , and a ligand that associates with and quenches a fluorescent polymer is disclosed . when an analyte sample is introduced , the ligand binds to a target biological agent if it is present , thereby causing the qtl molecule to separate from the fluorescent polymer resulting in an increase in detected fluorescence . the same chemistry is advantageously employed in a competitive assay . an electric field can also be applied to separate the qtl molecule from the fluorescent polymer . a method for detecting targets for these methods are also disclosed .