(Invited) Applications of Nanoparticles for Reactive Oxygen Species (ROS) Scavenging in Photosynthetic Systems

Cerium oxide nanoparticles, or nanoceria (NC), offer a regenerative approach to scavenging reactive oxygen species (ROS). NC have been used to prevent retinal and neuronal degeneration, protecting cells against ROS and radiation damage. Unlike most scavengers, which undergo a depletion in activity upon ROS consumption, NC are regenerative; theoretically, they are able to scavenge for ROS indefinitely so long as a physiological pH is maintained. Our recent work has extended NC applications beyond the human body towards other biological systems, such as plants and chloroplasts. Like retinal cells, plant organelles undergo photodamage caused by ROS generation under continuous illumination. We have demonstrated that NC can regeneratively protect plant-extracted chloroplasts from ROS-induced photodamage to prolong extracellular activity for light-harvesting, energy applications. By engineering the polymeric wrapping around the NC particles, we have demonstrated the ability to tune nanoparticle uptake into the plant chloroplast. This platform has been extended to in vivo applications, where single-walled carbon nanotube (SWCNT)-based complexes have been used to monitor and image ROS flux inside intact plant leaves, enabling not only a photonic chemical sensor, but also a novel, nanobionic approach to augmenting photosynthesis and enhancing plant efficiency.