https://doi.org/10.15407/jopt.2017.52.091

Optoelectron. Semicond. Tech. 52, 91-99 (2017)

Viktor Dan’ko, Ivan Indutnyi, Yuriy Ushenin, Victor Myn’ko, Dirk Hegemann, Marianne Vandenbossche, Petro Shepeliavyi, Mariia Lukaniuk, Petro Lytvyn, Roman Khrystosenko

INVESTIGATION OF THE SENSITIVITY INHERENT TO SENSOR Au CHIPS WITH NANOSTRUCTURED SURFACE

The results of studying the sensitivity of surface plasmon resonance biosensor based on nanostructured Au chips have been presented. Periodic relief in the form of a grating with submicron spatial frequency was created on the Au chip surface by using interferential lithography with vacuum chalcogenide photoresists. The spatial frequency of a grating was selected from the conditions of proximity to Bragg reflection of surface plasmon-polaritons for the set operation wavelength of the biosensor (850 nm) and the refractive index of the studied environment (solution of glycerol in water). Functionalization of the operation surface of the chip was carried out using plasma-stimulated deposition of polymeric a-C:H:O films with the effective thickness 5 and 10 nm. It has been ascertained that (2…4)-fold increasing the biosensor sensitivity as a result of grating formation and the width of the operation range of the environment refractive index (n) have been defined by the depth of the grating relief and have not depended on the thickness of the functional polymeric nanolayer. This functionalization of the chip surface merely results in the shift of the operation range position to smaller values of n as compared to that of uncoated chips. The operation range position of the nanostructured sensor chip can be adjusted to the refractive index of the studied environment by rotation of the chip in the azimuthal direction.

Keywords: surface plasmon resonance, biosensor, interferential lithography, functional polymeric films