Enhancing sensitivity of SPR sensors by using nanostructured Au chips coated with functional plasma polymer nanofilms

The sensitivity of surface plasmon resonance (SPR) sensors operating in the Kretschmann configuration was investigated using Au SPR chips with a nano-grating surface functionalized via deposition of a-C:H:O plasma polymer films. The surface of the chips was nanopatterned in order to improve the sensitivity of the sensor, as compared with the sensitivity of standard Au chips with a flat (unstructured) surface. It was found that deposition of the plasma polymer nanofilms neither affected the degree of refractometer sensitivity enhancement, nor the width of the operation range of the environment refractive index (n), in which the enhancement was observed. Such functionalization of the chip surface merely resulted in the shift of the operation range position to smaller values of n in comparison to non-coated chips requiring deposition of stable functional films