Fig. 6.

PSI stabilized in microspheres is capable of generating photocurrent in a biophotovoltaic device. PSI microspheres in a biophotovoltaic device are capable of undergoing charge separation and injecting electrons into a semiconducting TiO₂ layer on an electrode. A. Photocurrent density dependence on light intensity of full-spectrum white light is reported. Light intensity is reported in photon flux density, PFD (μmol/m²/s). B. Photocurrent density dependence on light intensity for PSI-specific red actinic light is reported. Light intensity units are the same as panel A. C. Average photocurrent density was plotted against PFD to show the linearity of the response. D, E. Photocurrent density response is consistent over multiple light/dark cycles for both white (panel D) and PSI-specific red (panel E) light, respectively. The light intensity was 62.5 μmol photons/m²/s for the PSI-specific red actinic light and 350 μmol photons/m²/s for the broad-spectrum white light. F. The steady-state photocurrent density during light-on from panels D and E is quantified in panel F, with baseline current subtracted.