SBIR Phase II:Large-Scale Synthesis of Hollow Metal Nanospheres: Conversion of Batch Synthesis to Continuous Flow

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 ( less than 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.