SBIR-STTR Award

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is rooted in the development of a large-scale synthesis for the manufacture of highly uniform hollow metal nanospheres for use by the military in potentially contaminated zones of operation, in rural settings with limited access to healthcare laboratories, or in the agricultural field for faster and more affordable detection of lower levels of food-based toxins and pathogens. Furthermore, establishing a source of these next-generation metal nanoparticles at commercially relevant levels of quality and quantity with consistent and predictable performance would pave the way for their expansion into other industries that could also benefit from their advantages, such as photocatalysis, water purification, and photomedicine. This Small Business Innovation Research (SBIR) Phase I project will scale-up the production of hollow metal nanoparticles from the existing small-batch syntheses to a large-scale continuous flow process, with strict standards for the control of their size, shape, and optical response. Large-scale synthesis of highly uniform hollow metal nanospheres with controllable size has not been achieved to date, hampering the use and study of these advanced materials. A high-quality, high-volume production method will position hollow metal nanospheres for rapid commercial adoption in applications where they markedly outperform their solid counterparts, such as in color reporting for lateral flow assays (LFAs), where hollow gold nanospheres can offer a 10-fold improvement in assay sensitivity. The primary objective of the proposed work is to determine the parameters necessary for a high-quality, high-throughput synthesis based on continuous flow, including reactor materials, chamber dimensions, precursor concentrations, flow rates, and reaction times. The major technical hurdle lies in the identification (within a very large parameter space) of suitable conditions for a successful and controlled synthesis; accordingly, a major component of this project is in-depth analysis and characterization of synthesized nanoparticles by optical spectroscopy and electron microscopy. Characterization results will be used to inform iterative reactor improvements. The resulting high throughput reactor will both advance the state of the art of nanomaterial synthesis and enable new research by creating a consistent supply of commercially available hollow nanoparticles with reproducible physical properties. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

The broader impact of this Small Business Innovation Research (SBIR) Phase II project is based upon establishing a consistent, reliable source of high-quality hollow metal nanoparticles, thus enabling their commercial adoption in applications where they markedly outperform their conventional counterparts. One such application is point-of-use testing: by switching to hollow metal nanoparticles, lateral flow assays will reach higher levels of sensitivity and lower limits of detection, improving field testing for environmental contamination; detection of toxins and pathogens in agriculture; and early disease identification in clinical and veterinary care. Integration into rapid antibody and antigen tests for highly contagious diseases such as COVID-19 should prove particularly impactful, as the resulting higher sensitivity would reduce the occurrence of false negative results, thereby improving the performance (and public perception) of rapid testing. Critically, it would also improve baseline testing availability for rural and under-served populations who do not have access to PCR-equipped clinical laboratories. They can be applied to many other industries as well. This Small Business Innovation Research Phase II project will advance the state of the art of continuous flow synthesis of plasmonic nanomaterials. Nanoparticle synthesis is a highly sensitive process, and obtaining high quality samples of advanced architectures has previously required labor-intensive, small-batch processes incompatible with large-scale production. Simply scaling traditional batch techniques has led to product with poor quality and prohibitive costs. This project advances a prototype reactor that has demonstrated high-throughput production of hollow plasmonic nanoparticles with control over size and color, while maintaining structural uniformity (<15% CV). Importantly, it reduced the cost of labor per liter of product by 950% from that of small batch synthesis. The proposed project will increase fidelity, further scale production volume, post-process and stabilize the final product, and benchmark its optical performance. The resulting production-scale reactor will have the capacity necessary to supply LFA manufacturers with ready-to-use, advanced color labels. It will enable new research and new nano-enabled devices by creating a consistent commercial supply of high performance plasmonic nanostructures with well-controlled physical properties. The manufacture of hollow metal nanoparticles for point-of-use testing applications will also pave the way for their expansion into other industries that would also benefit from their advantageous optical and photothermal plasmonic properties, such as photocatalysis, water purification, and phototherapeutics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.