Core–Shell–Shell Upconversion Nanoparticles with Enhanced Emission for Wireless Optogenetic Inhibition

• DOI: 10.1021/acs.nanolett.7b04339
• Publication Date: 2017-12-26T20:30:27Z
• Authors: Xudong Lin; Xian Chen; Wenchong Zhang; Tianying Sun; Peilin Fang; Qinghai Liao; Xi Chen; Jufang He; Ming Liu; Feng Wang; Peng Shi
• Keywords: Photon Upconversion; Opsin; Ytterbium; Halorhodopsin

Recent advances in upconversion technology have enabled optogenetic neural stimulation using remotely applied optical signals, but limited success has been demonstrated for inhibition by this method, primarily due to the much higher power and more red-shifted excitation spectrum that are required work with appropriate inhibitory opsin proteins. To overcome these limitations, core-shell-shell nanoparticles (UCNPs) a hexagonal phase synthesized optimize doping contents of ytterbium ions (Yb3+) mitigate Yb-associated concentration quenching. Such UCNPs' emission contains an almost three-fold enhanced peak around 540-570 nm, matching commonly used protein, halorhodopsin. The UCNPs utilized as transducers develop fully implantable upconversion-based device vivo tetherless inhibition, which is actuated near-infrared (NIR) light irradiation without any electronics. When implanted into targeted sites deep rat brain, electrical activity neurons reliably inhibited NIR restores normal level upon switching off light. system further perform unilateral secondary motor cortex behaving mice, achieving control their functions. This study provides important useful supplement toolset, beneficial both basic translational neuroscience investigations.