Fig. 1. Schematic of measurement setup

Fig. 2. WGM laser output of single DG microsphere in water. (a) WGM resonance peak at different pump powers;(b) curve of laser output intensity with pump power, the lasing threshold is 2.63 nJ

Fig. 3. Diagrams of phagocytosis of DG microspheres by T47D cells. (a)--(h) Showing the cell fluorescence confocal images at eight different moments, respectively; (i)--(l) represent fluorescence confocal images of fixed T47D cells containing DG microspheres, the nucleus is stained by PI, and the marker 1 part is the nucleus, while the marker 2 part is the microsphere; (i) light field image of cell; (j) fluorescence image of nuclear (PI staining, absorption wavelength is 535 nm and radiation wavelength

Fig. 4. Confocal imaging of T47D cells after endocytosis of DG microsphere. (a) Three-dimensional reconstruction of two cells; (b) a cross section of cell shows that the microspheres do exist inside the cell

Fig. 5. Laser output of DG microspheres within a single cell. (a) Typical WGM spectrum reaching threshold output in cell; (b) relationship between laser output intensity and pump energy

Fig. 6. WGM resonant wavelength of a single DG microspheres in different cells. (a) DG microspheres in SKBR3 cells; (b) DG microspheres in T47D cells; (c) DG microspheres in MCF7 cells; (d) central resonance peak of WGM of DG microsphere in different cells, and the illustrations are fluorescent field images of DG microsphere in different cells