Abstract: The present disclosure describes various improvements for programmable nuclease-based detection assays. Also provided are compositions, methods, kits, systems, and devices for practicing the same. Such improvements include improved reporter designs to facilitate the cleavage of a reporter immobilized on a substrate by an activated programmable nuclease. Improved reporter designs may comprise various lengths and structures of the reporter. The substrate can also comprise immobilized guide nucleic acids and/or programmable nucleases.