This Small Business Technology Transfer Program (STTR) Phase I project will create a new salmonella sensor combining two established tools in biodetection: hydrodynamic chromatography and magnetic nanoparticle (MP) conjugation. The proposed sensor will be significantly less expensive and provide faster detection time with equivalent sensitivity compared to current techniques. The project will develop this sensor by exploiting the connection between the MP magnetic orientation, fluid behavior and volume characteristics. Functionally coated MPs will be combined with a salmonella aptamer biomarker in a microfluidic channel. A magnetic profile of the solution will be measured using ultrasensitive giant magnetoresistance sensors. The MP magnetic profile will change in the presence of the biomarker due to modification of the MPs? hydrodynamic volume. The goal of the Phase I program will be to demonstrate this difference in magnetic profiles. Successful completion of the program will result in a prototype sensor for food safety applications in the Phase II effort.
The broader impact/commercial potential of this project could include food safety and medical applications. In the sizeable food processing industry the sensor is a highly efficient contamination monitor leading to dramatic improvements in food safety by preventing distribution of contaminated products. While the initial sensor will be designed for salmonella, the sensor is also extensible to other biomarkers and could be envisioned as a critical point-of-care sensor in the medical industry. The National Science Foundation?s mission will also be carried out by having graduate students and postdoctoral researchers participate in the program, exposing them to industry while developing new knowledge and honing their research skills.
The goal of this Small Business Technology Transfer Phase I program was to demonstrate the feasibility of a magnetoresistance-based lab-on-a-chip pathogen detector for Salmonella and demonstrate that the sensitivity and the speed of the novel sensor is superior to the existing technologies. The developed lab-on-a-chip technology is a revolutionary combination of magnetic nanoparticles functionalized with DNA aptamers and selective to live salmonella, etched microfluidic channels, and giant magnetoresistance (GMR) sensor elements. NVE is proud to report the successful real-time detection of individual live Salmonella. Through the course of the Phase I Program the following technical objectives were accomplished: Successful production of the DNA molecules (aptamers) through collaboration at the University of Minnesota (UMN). Designed and fabricationed the high sensitivity GMR sensor onto extra-thin silicon substrates at NVE. UMN and NVE collaboratively developed a process to fabricate a microfluidic channel on the back-side of the substrate, preserving the sensor functionality and drastically reducing the separation between fluid and sensor to 200 nm. Evaluated the sensor with/without flow, with nanoparticles and ferrofluds, selecting the best configuration for detection. Synthesis of Iron oxide nanoparticles and subsequent functionalization with aptamers. Verification that the functionalized particles attach only to salmonella bacteria. Detection of salmonella attached to magnetic nanoparticles through aptamers using our demonstration lab-on-a-chip.. This project advanced the knowledge and the understanding of how different branches of technology are merged to create a superior sensor. The sensor itself helps to better the general public by further improving food safety through providing a low cost, high throughput, readily deployable test that the industry crucially needs to stop an outbreak of salmonella poisoning before infection occurs. A cursory advantage is that the sensor is can also be used clinically to assist in the rapid detection if salmonella poisoning is suspected. This combination of technologies is also highly extensible to other pathogens of concern, e.g. listeria and e-coli. In summary the benefits to society are clear. This project transfers the technology developed through the course of academic research in several areas into a manufacturable industry-grade sensor. The sensor represents a significant break from state-of-the-art DNA or antibody based sensors by taking advantage of the properties of magnetic particles in a format that can be used in a high volume, continuous flow environment. The success of the project was possible thanks to an interdisciplinary team and a capable small business with significant experience in leveraging new scientific ideas into novel products.
