This paper presents an on-chip, filter-less fluorescence detector using an all-digital, time-resolved imager based on a CMOS single-photon detector array with limited in situ processing. The device comprises an array of pixels capable of detecting single photons integrated with time gating circuitry and a 1-bit memory. The sensor allows on-chip, filter-less fluorescence detection and fluorescence lifetime imaging microscopy (FLIM) for micro total analysis systems (μ-TAS) and point-of-care testing (POCT) applications. The sensor was tested as an on-chip optical DNA detector using Cy5 labeled DNA molecules directly placed on the sensor surface.