Numerical Analysis of the Optical Behavior of Semi‐Ordered Plasmonic Nanohole Arrays for Biosensing in Human Fluids

The development of advanced transducers is essential for technological progress in the health sector. This study reports the fabrication and numerical analysis of a plasmonic transducer based on random nanohole arrays, with potential applications in disease detection, biosensing, and biomarker identification. The work focuses on understanding its optical behavior while addressing the challenges of simulating randomly structured configurations that reflect realistic fabrication conditions. The transducer was fabricated using colloidal lithography, electron‐beam evaporation, and air plasma treatment. To model the experimentally observed random nanohole distributions, three‐unit‐cell geometries were simulated: rectangular, hexagonal and extended hexagonal. These configurations reproduce recurring morphological patterns, particularly a “star array” in which a central nanohole is surrounded by 4–6 neighboring holes. This pattern guided the design of the simulated cells. The position and characteristics of the LSPR were evaluated in transmission, reflection and absorbance spectra, along with the associated electric field distribution. The biosensing performance was also assessed through simulations using theoretical and experimental refractive indices of human fluids such as urine and blood plasma. The simulations revealed a mean LSPR wavelength of 657 nm and a bulk sensitivity of 173.08 nm/RIU. Additionally, the simulations demonstrated the ability of the plasmonic transducer to discriminate between different human fluids based on their optical responses. These results highlight the essential role of numerical simulation in optimizing the transducer's design and providing a solid foundation for its subsequent experimental verification in biomedical sensing applications.