We developed a one-minute, one-step SARS-CoV-2 antigen assay based on protein-induced fluorescence enhancement of a DNA aptamer. The system showed significant selectivity and sensitivity towards both nucleocapsid protein and SARS-CoV-2 virus lysate, but with marked improvements in speed and manufacturability. We hence propose this platform as a mix-and-read testing strategy for SARS-CoV-2 that can be applied to POC diagnostics in clinical settings, especially in low- and middle-income countries.