LAUSR

Abstract: The present study demonstrates the synthesis of cerium oxide nanoclusters (CeO2-NC) and its application towards detection of reactive oxygen species (ROS). ROS are generated due to exogenous exposure to oxidants, car smoke, pollutants etc. as well as endogenously as a byproduct of metabolism that can cause cellular damage. Although, protective antioxidant molecules and antioxidant enzymes are present to combat these oxidative damages in vivo, the overload of oxidants may lead to escape this combat pathway and expose us with a chronic low dose of oxidants creating oxidative stress. Thus, detection of ROS in biological fluids may lead us to combat the possible damage caused by the oxidant. Our synthesized nanoclusters are of extremely low size, highly stable and have a very high fluorescent property. Moreover, CeO2 nanostructures have been known to exhibit dual property; to act as a prooxidant as well as a free radical scavenger. We have utilized these properties to design a nanobiosensor which can detect ROS with high sensitivity. We have used hydrogen peroxide (H2O2) as a ROS generator and ascorbic acid as a free radical scavenger to react with the synthesized CeO2-NC and monitored the fluorescence intensity change. Our CeO2-NC exerted oxidants thereby increased the fluorescence intensity with H2O2 and decreased fluorescence with ascorbic acid. The fold increase or decrease in fluorescence intensity was linear. Thus, with the results obtained we can propose that CeO2-NC can act as an ROS nanobiosensor.