We investigated graphene-oxide-(GO-) coupled surface plasmon resonance (SPR) detection sensitivity for sandwiched antigen-antibody interaction between human and antihuman immunoglobulin G molecules. GO was prepared in a Langmuir-Blodgett solutionon gold and dielectric surfaces. Theoretical and experimental data suggest thatanincreased dielectric spacer thickness reduces resonance shifts for GO-coupled SPR detection as dielectric properties of GO appearto prevail. In general, a metal-enhanced structure was shown to provide a larger resonance shift by plasmonic field enhancement. The far-field properties were described in terms of near-field overlap. The peak resonance shift that was obtained with GO-coupled SPR detection was enhanced to 113% of the resonance shift obtained by conventional thin-film-based SPR detection and may further be improved by GO stacking.
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© 2014 Optical Society of America.