Disclosed are multichromophores, and methods, articles and compositions employing them. Disclosed are methods, articles and compositions for the detection and analysis of biomolecules in a sample. Provided assays include those determining the presence of a target biomolecule in a sample or its relative amount, or the assays may be quantitative or semi-quantitative. The methods can be performed on a substrate or in an array format on a substrate. Disclosed are detection assays employing sensor biomolecules that do not comprise a fluorophore that can exchange energy with the cationic multichromophore. Disclosed are biological assays in which energy is transferred between one or more of the multichromophore, a label on the target biomolecule, a label on the sensor biomolecule, and/or a fluorescent dye specific for a polynucleotide, in all permutations.