Development of In Vivo Nanosensors Using Organic Color Centers

Covalent bonding of organic functional groups to the sp2 carbon lattice of single-walled carbon nanotubes produces tunable sp3 quantum defects that fluoresce brightly in the second near-infrared region (NIR-II, 1000-1700 nm). Such synthetic defects, also known as organic color centers (OCCs), provide a molecular focal point that sensitively and selectively responds to the local dielectric environments. To take advantage of these unique electronic and optical properties of OCCs for biomedical applications, we discuss a new method that controls the biological interactions/biocompatibility of OCC-based nanosensors via their supramolecular interactions with polymers and other excipients. The resulting nanosensor sensitively detects local intracellular environments in live cells and in vivo. We assess the utility of the nanosensor for cancer research.