Photographs of (A) magnetic upconversion nanophosphors solution in a glass tube with a magnetic film in the tube (black rectangle) at t=0 min, (B) magnetic upconversion nanophosphors fluid with captured in an array pattern the magnetic film (t=10 min), (C) captured magnetic upconversion nanophosphors held on magnetic film during rinsing PBS soluton, (D) magnetic film after the magnetic upconversion nanophosphors were released by the external field, (E) Upconversion luminescence of captured magnetic upconversion nanophosphors on magnetic film during rinsing with PBS solution (the size of luminescent area depends on the beam size of the 980 nm laser), (F) Upconversion luminescence of magnetic film after magnetic upconversion phosphors were released by external magnetic field.