Figure 7.

Upconversion nanoparticles can be used to excite genetically modified neurons. a,b) A schematic of the energy transfer mechanism of YbEr UCNPs, and results from their application in the NIR activation of channelrhodopsin illustrate NIR activated neuronal firing and neuronal depolarization. Reproduced with permission.^[164] Copyright 2016, American Chemical Society. c,d) Representative electron micrograph of polymer-coated UNCPs which were utilized to induce neurite outgrowth when incubated with cells and excited with NIR. Reproduced with permission.^[163] Copyright 2014, John Wiley & Sons.