Depth-Resolved Multispectral Sub-Surface Imaging Using Multifunctional Upconversion Phosphors with Paramagnetic Properties

Abstract

Molecular imaging is very promising technique used for surgical guidance, which requires advancements related to properties of imaging agents and subsequent data retrieval methods from measured multispectral images. In this article, an upconversion material is introduced for subsurface near-infrared imaging and for the depth recovery of the material embedded below the biological tissue. The results confirm significant correlation between the analytical depth estimate of the material under the tissue and the measured ratio of emitted light from the material at two different wavelengths. Experiments with biological tissue samples demonstrate depth resolved imaging using the rare earth doped multifunctional phosphors. In vitro tests reveal no significant toxicity, whereas the magnetic measurements of the phosphors show that the particles are suitable as magnetic resonance imaging agents. The confocal imaging of fibroblast cells with these phosphors reveals their potential for in vivo imaging. The depth-resolved imaging technique with such phosphors has broad implications for real-time intraoperative surgical guidance.

Photovoltaic Effect-Based Multifunctional Photodetection and Position Sensing Using a 3C-SiC/Si Heterojunction

“…10−12 purposes, such as multispectral imaging, biomedical imaging, and advanced optical communication. 13,14 In terms of advanced semiconductive materials for harsh environments, silicon carbide (SiC) is one of the best candidates because of its superior mechanical properties, high thermal conductivity, and great chemical inertness. 15,16 This wide-bandgap semiconductor (2.3−3.2 eV) is more electrically stable at high temperatures than silicon (1.12 eV).…”

“…The photovoltaic effect in semiconductive heterojunctions refers to the conversion of photon energy into electrical signals. , Under the illumination of light, electron–hole (e–h) pairs are generated, separated by the heterojunction, and collected by electrodes on two sides of the substrate. This sensing effect has been employed to develop a wide range of photodetectors and solar cells. − For instance, photovoltaic effect-based photodetectors have been applied to different purposes, such as multispectral imaging, biomedical imaging, and advanced optical communication. , …”