Nanoprisms in plasmonic sensing: A comprehensive analysis of geometric effects

The highly sensitive and versatile technique of plasmonic sensing has been widely employed in detecting and analyzing chemical or biological substances. This work employs classical electrodynamics methods to investigate the sensing performance of nanoprisms systematically. By varying heights, base edge lengths, and rounding radii of base corners of triangular nanoprism, we explore their influence on sensitivity and the figure of merit (FOM) in both transverse and longitudinal polarization cases. Our findings indicate that enlarged triangular prisms exhibit enhanced sensitivity, but a decrease in FOM counterbalances this improvement. Conversely, reducing the rounding radius of the base corners of the triangular prism leads to simultaneous improvements in sensitivity and FOM. We suggest prioritizing triangular or tetrahedral prisms in fabricating nanosensors for higher FOM or sensitivity, respectively. These insights provide valuable directions for designing and optimizing plasmonic sensors in practical usage.