Plasmonic enhancement of photocurrent generation in Photosystem I–based hybrid electrode
We experimentally demonstrate that oriented assembly of red algal photosystem I (PSI) reaction center on a plasmonically active Silver Island Film (SIF) leads to strong enhancement of both fluorescence intensity and photocurrent generated upon illumination. PSI complexes were specifically attached to a monolayer of graphene deposited on the SIF layer. The results of comprehensive fluorescence microscopy point out to the critical role of the SIF layer in enhancing the optical response of PSI, as we observe increased emission intensity. Hence, importantly, the strong increase of photocurrent generation demonstrated for the biohybrid electrodes, can be directly associated with the plasmonic enhancement of optical and electrochemical functionalities of PSI. The results also indicate that the graphene layer is not diminishing the influence of the plasmonic excitations in SIF on the absorption and emission of PSI.