Lanthanide doped Upconversion Nanoparticles: A Nanoprobe used to calculate NIR attenuation in Porcine tissue

Sandip Ghosh^1*, Surojit Chattopadhyay¹

¹Institute of Biophotonics, National Yang-Ming University, Taipei City, Taiwan

* Presenter:Sandip Ghosh, email:ghosh.sandip36@gmail.com

A NIR (980 nm) absorbing phosphor, known as upconversion nanoparticles (UCNPs), is used as a probe to estimate the penetration depth of 980 nm light in Porcine tissue. We have used a Fluorolog spectrophotometer system to record the fluorescence emission intensity of the UCNPs (@540 nm) while exciting with 980 nm laser, that passes through different thicknesses (0-4 mm) of porcine tissue. The penetration of 980 nm light attenuates with increasing thickness of tissue. Finally, we noticed above 3 mm, 980 nm laser could not excite the fluorophore anymore and thus losing its ability to penetrate through the porcine tissue. This finding would bring more opportunity to applications of NIR lights in non-invasive therapies.

Keywords: Upconversion nanoparticles, Penetration depth, Biological window, Porcine tissue, Near-infrared