The novelty of this proposal lies in: (1) Fluorescent Ag nanoclusters (a few Ag atoms) are used as the fluorescent component, which can overcome the size increase issue of the current practice. (2) The capping agents of iron oxide nanoparticles are directly used as templates for Ag nanocluster formation under UV-radiation without the addition of other chemicals, which avoids tedious synthetic procedures. Besides the routine structural and physicochemical characterization of the proposed integrated nanostructures, detailed photophysical properties of Ag nanoclusters on nanoparticle surfaces will be explored with fluorescent correlation spectroscopy. Further, the structural integrity of the integrated nanostructures will be tested in biological systems. The proposed work will offer fundamental insight into the integration of multiple nanocomponents (e.g., correlations between structure-properties-performance).
NON TECHNICAL SUMMARY Magnetic nanoparticles have significantly advanced cancer treatments through targeted drug delivery and localized therapy and further make simultaneous therapy and diagnosis possible as magnetic resonant imaging (MRI) contrast agents. Unfortunately, these applications are limited by the expensive MRI equipments, which are not available to common research laboratories. Currently, fluorescence imaging remains the primary choice for bio-imaging because of its high sensitivity. This proposal will develop magnetic-fluorescent nanoparticles which provide a single platform with therapeutic and diagnostic functions. Beyond the new possibilities of this nanostructure in biomedical fields, further findings on the photophysics of Ag nanoclusters on nanoparticle surfaces may provide valuable information to physicists and spectroscopists. The integrated nanostructures may be used for monitored magnetic removal of the contaminants from the environment. Part of the research project will be incorporated in the junior summer laboratory course (ChBE320), a five hour laboratory operation class, promoting students? learning through hands-on experience, such as building alternating current (AC) magnetic coils to study the heat generation from magnetic nanoparticles and creating magnetic-fluorescent nanoparticle arrays on a chip to demonstrate the bio-sensing capability.
Magnetic-fluorescent nanoparticles have great potential in biomedical applications because the iron oxide nanoparticles can be clinically used as contrast agents for magnetic resonance imaging inside human body, and the additional fluorescent properties can provide high sensitivity for tracking and imaging outside human body. In this project, we have successfully created the magnetic-fluorescent bifunctional nanoparticles based on iron oxide nanoparticles and fluorescent gold nanoclusters. These integrated nanoparticles are magnetically responsive and exhibit bright red fluoresces. In addition, these nanostructures are very stable in biological media, such as cell growth media and biological buffers. The research results from this project are an integral part of the nanoscience lectures and laboratory demonstrations given by the PI’s group at various outreach activities. For example, The PI is an active participant of the NSF sponsored "Introducing Science Faculty from Historically Black Colleges and Universities (HBCU) to Materials Science and Engineering" workshop. Lectures on "Biomedical Applications of Multifunctional Nanoparticles", along with 1.5 hour research demonstrations and experiments were presented at the workshop for two years for HBCU faculty members. The PI’s group also provided both lecture and in-class demonstrations for the Nanoscience and Nanotechnology module at the 35th Annual Southeast Consortium for Minorities in Engineering (SECME) Summer Institute workshop.
