Development of a Nanohoop Rotaxane For Sensing Reactive Oxygen Species

1 page.Observing biological processes such as disease progression and gene expression require elaborate probes and sensors. In biomedical research, there is interest in making a multifunctional and modular scaffold that can target specific analytes by having a system that is “triggered” by the analyte which then affords a turn-on fluorescent response. Carbon nanohoops, or [n]-cycloparaphenylenes ([n]-CPPs) are a new nanostructure that allows us to observe biological processes by incorporating it into a larger structure called a rotaxane. Inspired by this model, we developed a novel modular probe system using a boronic ester trigger to detect reactive oxygen species (ROS). We began by synthesizing the rotaxane via copper-catalyzed azide-alkyne cycloadditions (AT-CuAAC), an active template method familiar to us and has demonstrated efficiency in previous publications. Once the structure was made, we characterized and analyzed it by subjecting it to simple non-biological environments and introduced ROS to see if the turn-on fluorescence is due to dethreading of the rotaxane. Success of the system is indicated by a turn-on fluorescence when reacted with these ROS and this shows that nanohoop-based [2] rotaxanes are tailorable for use in biomedical research