Figure 3: CLSM images of A549 cells treated with UCNPs@silane when irradiated by 980 nm laser, and the green channel (a: 540 ± 20 nm) and red channel (b: 660 ± 20 nm) images are corresponding to the green and red light emissions of UCNPs.

The inset is the upconversion emission spectrum monitored by CLSM with the step of 3 nm and the bandwidth of 15 nm. (c) is the merged image of (a) and (b), and (d) is the bright field image. The scale bar is 100 μm.