Analysis of a dual peak dual plasmonic layered LSPR-PCF sensor – Double peak shift sensitivity approach

In this article, a sensor that operates on the principle of localized surface plasmon resonance (LSPR) with the parallel implementation of aluminium doped zinc oxide (AZO) and gallium doped zinc oxide (GZO) is proposed. Due to the presence of two plasmonic materials in the sensor, it demonstrates two separate resonance peaks with a distinctive dispersion relation. Optimization of design parameters was performed in an innovative approach, employing double peak shift sensitivity method. This proposed sensor has the potential to identify undefined analytes with a refractive index spanning from 1.30 to 1.41, exhibiting a double peak shift sensitivity of 10,890.35 nm/RIU. Additionally, the sensor displays the highest amplitude sensitivity of 11,609.67496 RIU−1 and spectral sensitivity of 11,088.5 nm/RIU, as well as a high figure of merit of 1558.83. However, the sensor attains a maximum amplitude resolution of 8.614 × 10−7 RIU and a maximum wavelength resolution of 9.874 × 10−6 RIU with maximum linearity of R2 = 0.9962, implying an outstanding detection accuracy with a maximum limit of detection (LOD) up to 10−11 order. The primary drawback of conventional plasmonic metals like gold and silver is that they restrict the practical use of plasmonic devices. Therefore, our proffered sensor introduces a new way of interrogation of biomedical analytes such as cancerous cells, malaria-infected phases and blood components, applying alternative materials.