Simulation of Optical Biosensor Based on Anodic Nanostructured Niobium and Tantalum Oxides

Abstract

One of the promising areas of label-free analysis is optical biosensors based on 2D photonic crystals created from an array of nanopillars. The disadvantage of such crystals, usually formed on the basis of silicon and its dioxide, is the use of photolithography technology. The use of photonic crystals based on self-organized systems, such as arrays of niobium and tantalum oxide nanopillars obtained by anodizing two-layer Al/Nb and Al/Ta systems, allows us to solve this problem. The optical properties of photonic crystals based on arrays of niobium and tantalum oxide nanopillars were simulated. The sensitivity of the biosensor was determined by the shift of the main reflection peak relative to its position when filling the voids between the nanopillars of photonic crystals with air and biotin-streptavidin. The reflection spectra were estimated for specific and non-specific binding of biotin-streptavidin to the surface of photonic crystals. The intensity of the main reflection peak of the bio sensor based on tantalum oxide with a metallic Ta sublayer was 0.41 rel. units at a wavelength of 353 nm, the shifts of the peaks with a refractive index distribution of 1.46 for specific and non-specific binding were 12 and 24 nm, respectively. The intensity of the main reflection peak of the biosensor based on niobium oxide with a metallic Nb sublayer was 0.51 rel. units at a wavelength of 371 nm, the shifts of the reflection peaks with a refractive index distribution of 1.46 for specific and non-specific binding were 12 and 31 nm, respectively.