Engineering Hexagonal Array of Nanoholes for High Sensitivity Biosensor and Application for Human Blood Group Detection

In this study, the design of refractive index sensor with high sensitivity would be provided. This consists of a metal substrate with two metal-insulator-metal waveguide and an array of hexagonal nanoholes. Using the refractive index model obtained for different blood groups A, B, and O, we show that the structure can be used as a sensor to determine a human blood group. We used the array of nanoholes due to the unique optical properties, which leads to nanoscale confinement, high sensitivity to surface, and low propagation losses. Based on the results, resonance wavelength has a linear relationship with the refractive index of a material that is placed inside the nanohole; this feature makes it easy to identify the material. Considering a tradeoff between the transmitted power, structure size, and sensitivity, finite-difference time-domain simulations show that the sensitivity can be as large as 3172 nm per refractive index unit. In general, our plasmonic sensor can promote the sensitivity through the phenomenon of plasmon exciting on the surface of the nanoholes and would have useful applications in the medical field such as determining blood group, hemoglobin, and deoxyribonucleic acid (DNA) quantification.