Near ultraviolet-wavelength photonic-crystal biosensor with enhanced surface-to-bulk sensitivity ratio

Abstract

We report the design and characterization of biosensors based on one-dimensional photonic-crystal reflectance filters operating at near-ultraviolet wavelengths. Rigorous coupled-wave analysis simulations predict an increased confinement of the resonant electric field at the surface of this biosensor as compared to previously fabricated near-infrared photonic-crystal biosensors. This change in the resonant electric field provides an improvement of over 4.5 times in the surface-sensitivity to bulk-sensitivity ratio, and therefore enables enhanced detection resolution for biomolecules adsorbed on the biosensor surface. These biosensors will be especially important for applications requiring the detection of small molecules or ultralow analyte concentrations.