Development and Characterization of a Diamond-Based Localized Surface Plasmon Resonance Interface

The paper reports on the fabrication of a localized surface plasmon resonance (LSPR) interface with nanocrystalline diamond (NCD) as overcoating. The LSPR interface is formed through thermal evaporation of a 4 nm gold film onto quartz substrates and postannealed at 800 degrees C. The resulting gold nanostructures (Au NSs) are further coated with nanocrystalline diamond (NCD) films produced by hot filament-assisted chemical vapor deposition (HFCVD) at 800 C. The influence of the NCD film thickness on the wavelength at maximum absorption (lambda(max)) was investigated by recording UV-vis transmission spectra in air. The experimentally obtained data were compared to the theoretically calculated one. The possibility to introduce chemical functions on the quartz/Au NSs/NCD interfaces was demonstrated by (i) photochemical oxidation of the NCD overcoating and subsequent reaction of the oxidized surface with perfluorodecyltrichlorosilane or (ii) chemical linking of the 4-nitrobenzene diazonium salt directly onto as-grown hydrogen-terminated NCD films.