Self-assembled plasmonic nanoparticles on vertically aligned carbon nanotube electrodes via thermal evaporation.

This study details the development of a large-area, three-dimensional (3D), plasmonic integrated electrode (PIE) system. Vertically aligned multiwalled carbon nanotube (VA-MWNT) electrodes are grown and populated with self-assembling silver nanoparticles via thermal evaporation. Due to the geometric and surface characteristics of VA-MWNTs, evaporated silver atoms form nanoparticles approximately 15–20 nm in diameter. The nanoparticles are well distributed on VA-MWNTs, with a 5–10 nm gap between particles. The size and gap of the self-assembled plasmonic nanoparticles is dependent upon both the length of the MWNT and the thickness of the evaporated silver. The wetting properties of water of the VA-MWNT electrodes change from hydrophilic (∼70°) to hydrophobic (∼120°) as a result of the evaporated silver. This effect is particularly pronounced on the VA-MWNT electrodes with a length of 1 μm, where the contact angle is altered from an initial 8° to 124°. Based on UV–visible spectroscopic analysis, plasmonic r...