Overview: Ionizing radiation has many applications in nuclear power, medicine and agriculture, but can have significant harmful effects on human health and public safety. Due to the deleterious effects of radiation exposure on human health, effective sensing methods are imperative to preventing accidental exposure. Current radiation detection methods are limited by difficulty of fabrication, slow response times, sensitivity, low clarity of readout, and portability. In this research, we propose a novel nano-biosensing approach in which, engineered polypeptides are used to template the formation of colored metal nanoparticle dispersions from colorless metal salts upon exposure to ionizing radiation. A multiscale model of nanoparticle formation kinetics will be developed in order to investigate physicochemical factors influencing the efficacy of this nano-biosensing approach. The proposed project will integrate cutting-edge research, education and outreach to high-school students in the states of Arizona and Montana. Intellectual Merit The research objective of this proposal is to carry out a fundamental investigation into polypeptidetemplated generation of metal nanoparticles as effective colorimetric nano-biosensors of ionizing radiation. The proposed research builds on our recent findings, which demonstrate that elastin-like polypeptides (ELPs) can effectively template maroon-colored dispersions of gold and gold-silver bimetallic nanoparticle from their respective colorless metal salts upon exposure to ionizing radiation. The plasmonic peak of these nanoparticles can be quantified using visible light spectroscopy, and is easily visible to the naked eye. In the proposed research, we will engineer ELPs such that the guest residue in the polypeptide repeat sequence is known to either reduce metal (e.g. gold) salts to nanoparticles or is known to bind metals (Objective 1). This investigation will lead to sequenceproperty relationships that will shed light on the fundamentals of polypeptide-mediated templating. In addition, we will investigate the role of each of the twenty amino acids in templating metal nanoparticles, and use this information to design minimal peptides that can be used as nano-bio sensing elements. We will develop a multiscale kinetics model in order to gain fundamental insights into the processes and physicochemical factors governing the proposed nano-biosensing approach (Objective 2). In this approach, water radiolysis will be modeled together with metal ion reduction and nanoparticle formation. In addition to physicochemical insights into the effects of pH, scavenging agents and polypeptide sequence efficacy on nano-biosensing, the multiscale model is anticipated to reduce the experimental burden in these systems. Broader Impacts The proposed approach is a novel colorimetric approach for sensing ionizing radiation, and will have a transformative impact on life sciences, human health and public safety. The simplicity and flexibility of this nano-biosensing approach is anticipated to have deep, broad, and immediate impact in several of these disciplines. The collaborative team will integrate key concepts from polypeptide engineering, radiation chemistry and biology, and mathematical modeling leading to a unique research, education, and outreach environment for graduate, undergraduate, and high-school students in the states of Arizona and Montana. We will develop collaborative projects and engender scientific dissemination using wikis. The wikis will also be employed for documenting open-source software and algorithms developed as part of this proposal, and will be made freely available to the public. We will develop novel experimental modules for high school students in the states of Arizona and Montana through collaboration with the Quanta Program at ASU. The collaborative nature of this program, involving graduate and undergraduate students, together with the investigators, will lead to effective outreach related to nanotechnology and biotechnology to high-school students.
|Effective start/end date||9/1/14 → 8/31/19|
- National Science Foundation (NSF): $299,570.00