Peng Zhang, PhD Department of Chemistry New Mexico Institute of Mining and Technology pzhang@nmt.edu Phone:(505) 835-6192 Personal Website

Title: Development of Nanoparticles with Photon Upconverting Property for Cancer Detection

Phosphor/fluorescent particles have been used for quite some time.  When shorter wavelength light (ultraviolet or visible) strikes the phosphor particles, colored light with longer wavelength(s) is emitted, a process called down-conversion.  The opposite effect also exists, where a phosphor particle is excited with an infrared or red light (longer wavelength) and emits blue/green/yellow color (shorter wavelength).  The latter process is called up-conversion.  Upconverting materials convert lower-energy light to higher-energy light, which is realized through excitation with multiple photons.  Materials with upconverting properties are much less common than those with down-converting properties.  Nanoparticles with multiphoton upconversion properties have great promise in such applications as biosensing, bioimaging, and photon dynamic therapy.  Compared to conventional fluorescent reporters, upconverting phosphors are insensitive to the environment, do not photobleach, can be multiplexed to a greater degree, have no autofluorescence background, and are excited by much smaller, portable light sources.

The ultimate goal of this project is to develop nanoparticles with photon upconversion properties, and apply them in sensitive cancer detection.  The proposed research will capitalize upon our recent results and advancement in nanoparticles synthesis and biosensor development.  Here we intend to a) optimize methods that can more systematically prepare upconverting nanoparticles, and b) to explore the applications of upconverting nanoparticles in breast cancer detection.  By the completion of this study, we will have evaluated the performance of the upconverting nanoparticles as applied to the sensitive detection of breast cancer.  We expect these upconverting nanoparticles to become a highly sensitive signaling element.

Studies have shown that early detection of cancers, breast cancer included, saves lives.  In general, the smaller the tumor when diagnosed, the better the chance of being treated.  The dramatically enhanced signal-to-noise ratio of the nanoparticles would allow us to catch the small number of cancer cells in the background of a large number of normal cells, a likely scenario at the very early stage of tumor development.