Fig. 7: Optical properties of fluorescent MNF-structured microsphere.

a The diagram of synthesis mechanism of fluorescent MNF-structured microsphere. b The optical image of fluorescent MNF-structured microsphere under UV light by the fluorescence microscope, showing intense blue-purple. The experiment was independently repeated a minimum of three times. c High resolution Al 2p and Sr 3d XPS spectra. d The EPR spectra of MNF-structured microsphere and fluorescence MNF-structured microsphere (the gray represented MNF-structured microsphere, the blue represented fluorescent MNF-structured microsphere). e The PL spectra with 320 nm excitations of MNF-structured microsphere and fluorescence MNF-structured microsphere (the gray represented MNF-structured microsphere, the blue represented fluorescent MNF-structured microsphere). f The internal SEM image of inside fluorescent MNF-structured microsphere. The insert SEM image of (f) was the whole fluorescent MNF-structured microsphere. The experiment was independently repeated a minimum of three times. g The EDS image of skeletons, (h) the EDS image of shells. i The photograph of the fluorescent MNF-structured microsphere under sunlight. j The photograph of the fluorescent MNF-structured microsphere under UV light. Source data are provided as a Source Data file.