Engineering Bright and Biocompatible Upconverting Nanoparticles for Biomedical Application

Fluorescent imaging is a robust tool for visualizing cellular biochemistry. However, dyes photodegrade and are not used for whole-body imaging because their UV/Vis-excitation cannot penetrate into deep tissue and can be carcinogenic. I designed novel “upconverting” nanoparticles for fluorescent imaging that are excited by harmless and deep-penetrating infrared light. They are biocompatible and are 15-times brighter than the current standard. Since these were readily applicable to imaging, I extended their application to light-triggered cancer therapy, demonstrating 60% cell killing in deep tumors. This invention has additional applications in biosensing, solar cells, and optogenetics.