Title : The emergence of two near-infrared windows for in-vivo and intraoperative sers
Two optically transparent windows are present in biology within the near-infrared (NIR) spectrum and are of significant interest for in vivo molecular imaging and spectroscopic detection. The primary rationale is that NIR light can penetrate deeper within biological tissues than visible light because tissues scatter and absorb less light at these longer wavelengths. The first clear window, defined as light wavelengths between 650 nm and 950 nm, is superior for in vivo and intraoperative optical imaging than visible light. The second clear window, the wavelength range of 1000 nm to 1700 nm, has been reported to further improve detection sensitivity, spatial resolution, and tissue penetration because tissue photon scattering and background interference are further reduced. In this presentation, I will discuss recent advances in developing biocompatible plasmonic nanoparticles for in vivo and intraoperative surface-enhanced Raman scattering (SERS) in both the first and second NIR windows. I will also present a new class of “broad-band” plasmonic nanostructures that are well suited for surface Raman enhancement across a broad range of wavelengths allowing a direct comparison of detection sensitivity and tissue penetration between the two NIR windows. These SERS nanoparticles are generally nontoxic and are much brighter than fluorescent agents, raising new possibilities for ultrasensitive detection of microscopic tumors and image-guided precision surgery.
Audience take away:
• The importance of the NIR transparency windows for in vivo optical imaging
• How intraoperative image guidance using nanoparticles can increase precision in tumor resections
• Why SERS offers unique advantages over more conventional fluorescence-based technologies for biological imaging applications