CPOS Seminar: "Benzopyrylium Polymer Platforms for Dynamic Nanoparticles with Tandem Near-IR Two-Photon Detection of Peroxynitrite"

Speaker:  Emile Morin, PhD Student, Department of Chemistry & Biochemistry -  Carlini Group, University of California Santa Barbara

The detection of peroxynitrite as a reactive oxygen and nitrogen species is vital to elucidating acute and dynamic states of disease. However, the potential for diagnostic imaging capabilities of current probes remains limited due to the intrinsic limitations of small molecule probes such as singular modes of response, rapid clearance rates, poor solubility, and limited modularity. By developing the highly responsive and selective benzopyrylium (BZP) based fluorophores into a polymeric system, we have established a novel platform of peroxynitrite sensing materials. The development of a broad range pH stable monomeric probe (BZP-M2) has enabled a ROMP based polymer that displays a multimodal dynamic response to peroxynitrite. This system combines near-IR two-photon emission fluorescence for high resolution and ratiometric sensing of peroxynitrite. Furthermore, block copolymers synthesized were successfully formed into discrete nanoparticles imaged with electron microscopy. These BZP based nanoparticles display a fascinating peroxynitrite-induced aggregation into intricate globular assemblies in tandem with their fluorescent response. This work advances stimuli responsive polymers for reactive oxygen species detection towards a modular and dynamic macromolecular approach that demonstrates architectural control, excellent selectivity, and high sensitivity. Establishing a platform of macromolecular peroxynitrite probes that further illuminate diseased states through prolonged and dynamic diagnostic imaging.