An optically integrated magnetic biosensor includes an optically detected magnetic resonance (ODMR) center and a fluidics layer configured to contain a solution comprising analytes, the fluidics layer being disposed over the ODMR center. A light source which generates incident light excites electrons within the ODMR center from a ground state to an excited state and a radio frequency (RF) antenna generates an RF field incident with frequencies which correspond to ground state transitions in the ODMR center. The ODMR center produces emitted light when illuminated by the incident light. The characteristics of the emitted light are influenced by the RF field and magnetic nanoparticles attached to the analytes. A method for detecting analytes using optically detected magnetic resonance is also provided.