With support from the Chemical Measurement and Imaging Program and co-funding from the Chemical Structure, Dynamics and Mechanisms-B Program in the Division of Chemistry, Dr. Julia Zhao and her group at the University of North Dakota are devising a new approach to chemical imaging based on graphene-based nanomaterials. When illuminated with light of the proper wavelength, these materials fluoresce in the near infrared (NIR) region of the electromagnetic spectrum. This offers lower background signals (and therefore higher sensitivity) and deeper penetration than conventional imaging agents. This in turns enables imaging the inner structures of biological and other, with important potential applications in areas such as environmental science, biology, and national security. Dr. Zhao is reaching out to engage Tribal Colleges and Universities in North Dakota both in this work and more generally. A key aim is to encourage students from this underrepresented group to consider science as a career option.
The technical objectives of this project are three-fold: 1) Synthesis. The development of a series of graphene-based near-infrared fluorescent (NIRF) nanomaterials for sensitive detection and imaging of trace analytes (especially in biosamples). The distinct features of these NIRF nanomaterials are: a) intense fluorescence signals, b) tunable fluorescence wavelengths, c) high water solubility, and d) large surface area. To achieve this goal, the PI is developing new methods for making graphene-based NIRF nanomaterials with various dimensions and reduction levels to fine-tune the fluorescence wavelengths and intensities. 2) Fundamental study. Study of the geometric, compositional, and dimensional effects of graphene materials on their fluorescence properties, including fluorescence quantum yield, lifetime and wavelengths. 3) Application. The implementation of the NIRF nanomaterials in bioanalysis and bioimaging. The NIR region favors low background signals and deeper penetration of radiation. Highly sensitive detection and in vitro/vivo imaging can be accomplished using NIRF nanomaterials. Targeted properties include high quantum yield, tunability of excitation and emission wavelengths, minimal photo-bleaching, and minimal overlap between excitation and emission bands.
