(Invited) Rational Design of NIR-II Optofunctional Materials for Biomedical Applications

Abstract

The second near-infrared (NIR-II) biological window operating in the wavelength range of 1000-1700 nm is of considerable current interest for biomedical applications. This is mainly attributed to the high biological tissue penetration depth of the NIR-II light because of the less absorption and low optical scattering. However, previous studies regarding NIR-II optical materials mainly focused on the fluorescent upconversion nanomaterials, carbon nanomaterials, organic molecules and polymers for fluorescent bioimaging, photothermal/photodynamic therapy, and photoacoustic imaging. As is well-known, these optofunctional materials have limitations of low fluorescence efficiency, poor stability and poor multifunctionality. This talk will introduce NIR-II plasmonic materials recently developed in our lab for biomedical applications. We have developed NIR-II plasmonic Au-Ag nanostructures, copper chalcogenides and their hybrids with excellent optical properties tunable by their size, composition and structure. We have demonstrated the excellent plasmonic properties of these materials and systematically elucidated their structure-plasmonic property relationship. We also exemplified the applicability of these NIR-II optofunctional materials for SERS biosensing, photoacoustic imaging, CT, and light-assisted cancer therapy with excellent performance. We believe that these NIR-II plasmonic materials hold considerable potential for multimodality theranostics of cancer.