The University of Texas at San Antonio (UTSA) in collaboration with its MRSEC Partner, Northwestern University (NU) are currently involved in studying and developing biological applications of nanoscale materials. This unique collaboration between UTSA and NU offers state-of-the-art facilities and expertise to investigate these materials as well as provide a broad and lasting impact to both future generations of scientists/ researchers and the world community. The UTSA- PREM program consists of six research thrusts. The focus of these six thrusts is:
- Rare Earth based multi-functional nanoparticle biosensor; Sardar (UTSA), Dravid (NU), and Szleifer (NU)
- Medical applications of nanoparticles - targeted contrast agents for use in optoacoustic detection of specific analytes with greatly enhanced sensitivity and selectivity; Glickman and Maswadi (UT Heath Science Center at San Antonio)
- Developing new and advanced characterization methods to study biological tissue using nanoparticles and electron microscopy techniques and studying the interaction of nanoparticles with cells; Yacaman and Lopez-Lozano (UTSA), De La Cruz, Odom, Van Duyne, and Mirkin (NU)
- Determine the toxicological effects and binding sites of Ag-Au nanoparticles, the diffusion properties of Ag-Au outside and inside single cells, and the functional nano-ablation effects of nanoparticles to further study neuronal function; Santamaria and Yacaman (UTSA)
- Terahertz characterization of nanomaterials for biological imaging applications; Peralta, Wilmink, and Roach (UTSA)
- Functionalization of fibers employing low temperature pulsed laser deposition and atomic layer deposition for power generation applications; Ayon, Chabanov and Chen (UTSA)
Academic collaboration among these groups is prevalent at UTSA, and their research topics are closely related and complementary to each other.
Notable Research Accomplishments
Figure 1. STEM images of gold nanoparticles and computer simulation models of the corresponding structures.
Recently progress has been made on understanding the properties of geometrical shapes of gold nanoparticles and nanoclusters (Figure 1). The goal of this project is to perform extensive experimental and theoretical studies. Installation of a second generation spherical aberration corrected scanning transmission electron microscope (STEM) will allow PREM researchers to begin development of a nanoparticle laboratory inside a high resolution STEM (better than 0.08 nm). Additional components of this microscope may include atomic force microscopy (AFM) and a sample holder with heater capable of annealing samples up to 1000oC inside the STEM in real time. Additionally, research is currently advancing on the development of composite rare earth and gold based nanocomposites. PREM students and faculty recently observed an enhancement of upconversion (Figure 2) in Er3+:Y2O3 and Er3+:Gd2O3 nanoparticles decorated with gold nanoseeds. These results are critical in the development of a multifunctional rare earth- based biosensor. PREM students are presently conducting experiments to determine multi-functional properties (absorption, fluorescence, magnetic, photoacoutic, and surface enhanced raman phenomena) of these systems under different geometries and physical conditions.
Education Outreach and Broader Impacts
Figure 2. Enhanced Er3+:Y2O3-Au fluorescence up-conversion transitions due to the surface plasmon resonances of gold (red) and Er3+:Y2O3 up-conversion without gold (black). Both samples were excited at 980 nm.
The UTSA-NU PREM collaboration offers a unique opportunity to underrepresented groups in materials science. UTSA is home to 29,000 students, of whom 58% are underrepresented minorities. Minority students will have the opportunity to work on PREM research thrusts and travel to conferences, Northwestern University, and events to integrate minorities into materials science. Currently, PREM faculty and students from NU and UTSA are developing a seed Research Experience for Teachers (RET) program to be held each summer at UTSA for several weeks. This program will impact the greater San Antonio area by incorporating San Antonio area high school teachers into the exciting research areas of nanoscience and materials science. The selected teachers will work on research projects in PREM laboratories and gain hands-on experience that will enable them to develop in-class curricula related to materials science. Finally, the UTSA department of Physics and Astronomy currently has a partnership with Northwest Vista College (NVC), a local community college, to pipeline minority students into the materials science world. Students complete a two-year nanotechnology program at NVC and enroll at UTSA to finish a bachelor’s degree of science in their respective field.
Figure 3. San Antonio high school students engaged in spectroscopic research at the UTSA Laser Research Laboratory during the summer of 2009.
During the spring of 2010, our partner NU-MRSEC Faculty met with UTSA-PREM faculty and students. Two NU faculty members presented research seminars to physics, engineering, chemistry, and biology students at UTSA. Additionally, NU faculty members met face to face with students and discussed the PREM research thrusts and education outreach efforts. These meetings provided students with the opportunity to explore and enhance their research at NU over the summer of 2010. Two undergraduate students and two graduate students have been selected to visit the NU-MRSEC over the coming summer to open up collaborations between the two institutions (UTSA and NU) and will work to discover new results in materials science. These summer visits will become a yearly tradition of the PREM collaboration.