The unprecedented COVID-19 pandemic highlights the need for portable, sensitive, and accurate biosensors. Here, a novel biosensor that takes advantage of localized surface plasmonic resonance (LSPR) through unique nanoscale geometries was fabricated for sensitive detection of biomarkers. The formation of an adaptable system capable of combining with other sensing methods, such as CRISPR-Cas13a assays, allowed for the detection of specific targets to be realized. In this system, streptavidin-coated gold nanoparticles (GNPs) hybridize with single-stranded RNA (ssRNA) before binding to the surface of gold nanomushrooms (GNMs). Through LSPR enhancement, this binding event produces a red shift in the resonance wavelength peak due to changes in the refractive index surrounding the GNMs. Various concentrations, shapes, and diameters of nanoparticles were investigated to determine the greatest possible resonant shift. Through this work, the use of streptavidin-coated 40 nm AuNPs produced the greatest redshift at ~30 nm for concentrations greater than 500 pM. Packaged in a microfluidic cell, the device offers a novel strategy for the detection of biomarkers with minimal sample preparation and rapid, label-free detection. Expanding this process to include CRISPR-Cas13a proteins incorporates the advantage of collateral cleavage which further enhances the sensitivity of LSPR, a critical and far-reaching bottleneck specifically of concern in label-free biosensing.
Materials Science and Engineering (MS)
Department, Program, or Center
School of Chemistry and Materials Science (COS)
Waitkus, Jacob T., "Localized Surface Plasmon Resonance Enhancement from Complex Nanoscale Geometries" (2022). Thesis. Rochester Institute of Technology. Accessed from
RIT – Main Campus