Fluorescent Nanodiamonds for Multiplexed Imaging and Diagnostics

Summary Under this projecta means for the creation of fluorescent nanodiamondFNDof multiple colors for multiplexed detection in biological assays will be developedFluorescent imaging is an ever increasingly important technique in biomedical research with a growing demand for fluorescent labels which are non toxicbrightphotostableand which can be easily derivatized with targeting ligandsNano sized crystallographic diamond can be made to contain fluorescent color centers by the appropriate processing of atomic lattice constituents to create complexes of impurity atoms and lattice vacanciesBecause these created fluorescent centers are embedded in the diamond latticethey are not susceptible to photobleaching as occurs with other conventional fluorophoresAlthough red FND has been commercially developedthere have been no means to create bright reproducible FND of other colorsBy adopting the method of rapid thermal annealing and using synthetic diamond particles with reproducible nitrogen content and positioning within crystallographic latticeprocessing conditions may be achieved to controllably produce color centers unattainable in a conventional thermal annealing processThe colors to be produced will be bluegreenand redbenchmarked for brightness against current commercial organic fluorophorsEach color may be excited by the same ultraviolet wavelengththereby improving the workflow of multi signal labelingAlternativelyall colors are accessible via two photon absorption of wavelengths from the rangenmallowing for increased tissue penetration and reduced background fluorescenceDue to exceptionally high biological compatibility and unique optical propertiesmultiplexing via FND has broad applications in immunological assaysflow cytometrycorrelative microscopy using multiple fiducial markerslabels for tissue scaffold engineeringand for tagging stem cells in regenerative medicineIn this projectspecific utility will be demonstrated using recently developed targeting ligands specific either for vascular endothelial growth factor receptorsorwhich represent potential targets for anti angiogenic anti cancer therapiesThe outcome of this research will be the demonstration of non toxicinfinitely photostable fluorescent diamond particles for use in cancer diagnostics Narrative This project develops non toxic fluorescent nanodiamondFNDof different colors for multiplexed detection in biological assaysProduction of FND with bluegreen and red fluorescence became possible due to using a recently developed rapid thermal annealing approach for controlled formation of color centers in diamondNanosized crystallographic diamond containing fluorescent color centers are not susceptible to photobleachingobserved in conventional fluorophorsand thereby have utility as a non toxic biomedical tool for cancer diagnosticsSpecific utility will be demonstrated using recently developed targeting ligands for anti angiogenic therapies