LANTHANIDE-DOPED NANOPARTICLES AS NIR-WINDOW BIO-IMAGING PROBES

Abstract

Bio-imaging in the Near Infrared (NIR) window benefits from 1) the eliminated autofluorescence background, 2) the reduced tissue absorption & scattering of light and 3) the minimized photodamage. Therefore, with NIR responsive probes, high quality in vivo images of excellent contrast and spatiotemporal resolution can be obtained in thick samples. Constant efforts have been made in developing NIR contrast agents of high brightness, good photostability, flexible emission wavelength and low toxicity. In this thesis, the photoluminescence properties of lanthanide-doped nanoparticles were explored and harnessed for bio-imaging studies and molecular detection. Three works are included: 1) the real-time visualization of intracellular motor protein at single upconversion nanoparticle level, 2) the investigation of Nd3+/Yb3+ based nanoprobes with high emission brightness and 3) the fabrication of upconversion barcodes for multiplexed molecular detection. The NIR luminescent nanoprobes developed in the thesis would have impact both on fundamental science and technological advances.