Enhanced photocurrent generation in self-assembled monolayers formed at plasmonic gold nanostructures

The effect of localized surface plasmon resonance (SPR) appearing at the surfaces of gold nanoparticles (AuPs) was successfully applied for the enhancement of photocurrents from porphyrin (Po) immobilized on AuPs. The electrode consisting of AuPs with different sizes (∼15 or ∼35 nm) was prepared using the AuP film formed at the liquid/liquid interface, and then Po was self-assembled on the gold surface. The SPR effect for the AuP film was verified from the attenuated total reflection SPR and absorption measurements. Photocurrents from the modified electrodes were compared with the corresponding planar electrode. Appreciable enhancement of photocurrents was observed.