In Vivo Whole Animal Fluorescence Imaging of a Microparticle-Based Oral Vaccine Containing (CuInSe x S2–x )/ZnS Core/Shell Quantum Dots

Zinc sulfide-coated copper indium sulfur selenide (CuInSe x S2–x /ZnS core/shell) nanocrystals were synthesized with size-tunable red to near-infrared (NIR) fluorescence with high quantum yield (40%) in water. These nanocrystals were tested as an imaging agent to track a microparticle-based oral vaccine administered to mice. Poly(lactic-co-glycolic acid) (PLGA) microparticle-encapsulated CuInSe x Se2–x /ZnS quantum dots were orally administered to mice and were found to provide a distinct visible fluorescent marker in the gastrointestinal tract of living mice.