A Bioengineering Approach to Nanoparticle based Environmental Remediation
|Principal Investigator||Daniel R Strongin|
|Relevance to Implications||Marginal|
|Class of Nanomaterial||Engineered Nanomaterials|
|Broad Research Categories||
Generation, Dispersion, Transformation etc.
|Anticipated Total Funding||$399,979.00|
|Anticipated End Year||2005|
The management of anthropogenic chemical toxins is a major environmental challenge. Various strategies have been employed to facilitate the degradation of this class of pollutant. Processes involving nano-sized materials have garnered interest because it is well known that nano-sized particles exhibit unusual thermal and photo-chemistry in a variety of chemical applications when compared to particles of larger dimensions. Our objective is to develop a bioengineering approach that can be used to develop nano-size catalytic materials as the basis for new remediation strategies. Here we propose a research program to assess the potential use of ferritin, and ferritin-derived compounds, as catalysts in environmental degradation processes. The ferritin system has the advantage of being environmentally benign and biodegradable. Ferritin is an iron-storage protein that consists of a native nano-size iron oxide core (ferrihydrite) encapsulated within a spherical protein cage (120 D diameter). Ferritin is commercially available, but it has also been cloned in our laboratory and can be produced in gram quantities. We have shown that the size of the iron oxide particles can be controlled to form homogeneous nanoparticles from 20 to 75 D. Also, the native iron oxide core of ferritin can be replaced by other metal oxides such as Mn and Co oxides. Such inorganic materials at more traditional size ranges (> micron) exhibit photocatalytic and catalytic activity in a variety of systems. Our hypothesis is that by assembling these materials as nanoparticles within the ferritin (i.e., the protein shell) we can “tune” their surface chemistry toward beneficial environmental chemistry through our control of their size and electronic structure. Furthermore, by the chemical functionalization of the ferritin cage, we can further alter the chemical reactivity of the nanoparticle. Our research focuses on: (1) the development of a bioengineered synthesis of a variety of homogeneous nano-sized metal and metal oxide particles; (2) the determination of the electronic properties of the nanoparticles and their reduced forms (i.e., the base metal) as a function of size; (3) a determination of the reactivity of the particles toward beneficial environmental chemistry, as a function of size and electronic structure.
The approach is to use our expertise in biomineralization to synthesize ferritin-like and ferritin-derived nano particles, concentrating initially on iron oxide and zero valent iron, but extending the research to other metal oxides and zero valent metals. The electronic structure and reactivity of these particles will be studied using a combination of modern surface science techniques as well as aqueous geochemical and photochemical techniques.
Our ultimate goal is to develop new nano-sized materials based on ferritin that may serve as catalysts in (photo)chemical degradation processes of common contaminants. We expect to gain significant insight into the dependence of electronic structure and reactivity on chemical composition of the nanoparticle.