1. 1Managed by UT-Battelle for the Department of Energy Presentation_name Molecular Photovoltaics and the Optical Activation of Neural Cells E. Greenbaum 1, M. S. Humayun 2, B. R. Evans 1, T. Kuritz 1, I. Lee 3, C. P. Pennisi 4 1 Oak Ridge National Laboratory, 2 University of Southern California, 3 University of Tennessee, 4 Aalborg University March 18-19, 2009 Oak Ridge, Tennessee

2. The Artificial Retina

3. 3Managed by UT-Battelle for the Department of Energy Presentation_name

4. 4

7. 7

8. PSI on a Heterostructure S SSS SSSSSSS Au PSI O H O H O H O H O H O H O H O H O H O H O H

9. Measurement of Electrostatic Potential in Nanometer- Resolution: Schematic Illustration Kelvin Probe Method in Lift Mode h a c b d – + + 0 V Au – + – Light 0 nm

10. 0 V 5 V -5 V 0 nm 15 nm 30 nm Light on Light on Light Off Light Off ab AFM and KFM Images of PS I Reaction Centers Immobilized on Gold Immobilized on Gold

11. PS I Photovoltage Topography: Summary of Three Types of Measurements The vertical arrows in above figure indicate three selected voltage points we used in this table: the two extremities and the center.

13. Conceptual Illustration of Idea

14. WERI-RbI retinoblastoma cells fused with (proteo)liposomes Add (proteo) liposomes WERI-RbI retinoblastoma cells fused with (proteo)liposomes and loaded with fura-3 Load with the fura-3 dye Illuminate with 600-700 nm

15. Spectral Properties of System

16. FIRST STEP: PSI RECONSTITUTION INTO PROTEOLIPOSOMES RECONSTITUTION

19. 19 Light triggers increase in cytosolic Ca 2+ in proteoliposome-treated cells

20. Kinetic Time Course Experiments in the Presence and Absence of PSI and External Calcium

21. 21 Spatial Distribution of the Electric Potential From Photosystem I Reaction Centers in Lipid Vesicles

22. 22 Distribution of the Electric Potential Close to a PSI Reaction Center Inserted in the Vesicle Membrane The Role of Ionic Strength 00.1 M IEEE Transactions on Nanobioscience, Vol. 7, No. 2, June 2008, Pennisi, Greenbaum & Yoshida