Abstract: A graphene oxide (GO)-silver nanoparticles (AgNPs)-Eu3+ fluorescent probe, a paper-based sensor, and a preparation method and use thereof are provided. The paper-based sensor is developed based on a GO-AgNPs-Eu3+ fluorescent probe-loaded polyvinylidene fluoride (PVDF) microporous membrane, which is further combined with a smartphone. The GO-AgNPs-Eu3+ fluorescent probe shows high selectivity for 2,6-dipicolinic acid (DPA), strong anti-interference ability, and low limit of detection (LOD) for the DPA and spores. The paper-based sensor realizes quantitative detection of the DPA and the spores through red, green, and blue (RGB) changes of the smartphone, and detection results are verified by an actual amount of the spores in milk and water. The rapid detection of foodborne spores is achieved through a dual-function platform based on fluorescence of the GO-AgNPs-Eu3+ fluorescent probe and the paper-based sensor.