Kyung A. Kang, University of Louisville, Ernst Hall 106, Speed School of Engineering, University of Louisville, Louisville, KY 40292, Jianting Wang, Chemical Engineering, University of Louisville, Ernst Hall 106, Speed School of Engineering, University of Louisville, Louisville, KY 40292, Michael H. Nantz, Chemistry, University of Louisville, Department of Chemistry, University of Louisville, Louisville, KY 40292, and Samuel Achilefu, Department of Radiology, Washington University in St. Louis, CB 8225, Room 1150, East Building, 4525 Scott Avenue, St. Louis, MO 63110.
Nanometal particles with high surface plasmon strength (e.g., gold, silver, platinum particles, etc.) can be highly effectively utilized in altering the level of emission from a fluorophore. The level of the change can be varied significantly, from complete quenching to extensive enhancement, depending upon the strength of plasmon field where the fluorophore is placed. The plasmon field strength depends upon the metal type and the size of the particle, the distance between a particle and a fluorophore, and the quantum yield of a fluorophore. For a system where the metal type and particle size are fixed, the distance between two entities is a manipulable factor, i.e., placing a spacer at a desired length between the two.
With the understanding the fluorescence quenching and enhancement properties of these metal particles, by intelligently designing the spacers between a fluorophore and a particle, we are currently developing a novel, FRET-like, nano-entity for highly specific cancer locator. When the design is successfully completed, one can also develop a multi-functional nano-entity by combining the tumor localization ability with cancer therapeutics, enabling seamless cancer detection/diagnosis and therapy.