Abstract: Trifunctional nanoparticles have excellent fluorescence, magnetism, and cell recognition, which can be easily manipulated, tracked, and conveniently used to capture target cells. The surface-immobilized molecules of the TFNs might be optionally changed on demand for the purposes of bioanalysis, biomedical imaging, diagnosis, and the combinatorial screening of drugs. The nanoparticle is formed from a mesoporous polymer; a magnetic material adhering to the mesoporous polymer; a fluorescent dye adhering to the mesoporous polymer; and a biomaterial coupled to the mesoporous polymer, where the mesoporous polymer has been treated with hydrazine, and the biomaterial has been treated with an oxidizing agent.