Assembly of biosolar cells by using N719-bacteriorhodopsin complex

     Today, using new and renewable energy sources to replace fossil fuels is greatly expanded. The solar cells are devices that convert solar energy to electrical energy. Solar cells based on organic materials, especially proteins, are one of these solar cells. For example, bacteriorhodopsin (bR) which is one of the membrane proteins in halobacterium salinarum could be used in solar cells and participate in the liberation and transfer of the electrons. In this study, the effort has been to add a chemical dye (N719) to protein and develop a new hybrid bR/Dye complex to increase efficiency of solar cells based on protein. The formed hybrid complex was tested by using of FTIR and other spectroscopy. Current and voltage of bacteriorhodopsin-based photocell was increased in new complex-based photocell. The results of AFM, FTIR and UV-Visible spectroscopy showed a smooth deposition of bR-Dye N719; stable complex of bR-Dye N719 was also formed

Application of Flexible Sheet in the Construction of Bio-Battery through Using Immobilized Bacteriorhodopsin

Introduction: Biophotovoltaic cells have often been studied due to their properties and their potential applications in micro and nano equipments. In order to enhance the quality and versatility of these bio-photocells, flexible sheets such as polyethylene terephthalate (PET) have been widely used. In this study, ZnO nanoporous films were used for immobilization of bacteriorhodopsin (bR) due to the it’s great surface area, measured against titanium dioxide (15TiO2 ). In addition to good conductivity, its superiority was proved by the arrangement of zinc oxide atoms at a suitable temperature. Materials and Methods: In the present study, bacteriorhodopsin was immobilized on ZnO-PET surface through modifying the PET as a photoanode in (Dye-Sensitive Solar Cell) DSSCs. Furthermore, a non-toxicity protein, bR, was substituted for sensitizing ZnO–PET nanoparticles in DSSCs instead of the common expensive chemical-based dyes such as ruthenium-based or organic dyes. Atomic Force Microscopy technique was used to study the morphology of modified PET-ZnO & PET- 15TiO2  surfaces before and after immobilization of bR. Results: AFM images show Signs of excellence in zinc oxide in the atomic arrangement. Finally, the typical I–V curves of the biomolecule-sensitized biosolar cell were obtained.  The results indicated that the overall conversion efficiency of the photocell is about 0.16%, a solar cell flux (Jsc) of 0.45 mA cm−2, an open-circuit voltage (VOC) of 0.57 V, and a fill factor of 0.62. Conclusion: Atomic composition of nanoparticles of zinc oxide at a suitable temperature is better than titanium dioxide. This makes the cell more efficient in transporting electrons. the efficiency of the cell produced on the PET bed is appropriate but requires more scientific research

Surface modification by using of immobilized electrostatic self-assembly of bacteriorhodopsin as protein memory

        Bacteriorhodopsin (BR) is the light harvesting and photoactive proton pump found in the membrane of a salt marsh bacteria. This protein has significant potential to use in optical computing and memory devices due to unique intrinsic physical properties of photo and bioelectric. All these features make BR one of the most promising protein candidates in protein memories. Protein memory is a kind of optical memory with a large storage capacity and high speed processing features. BR protein was used with the polymer film in order to create better stability. In order to investigate immobilization of electrostatic self-assembly of BR on glass and polycarbonate as protein memories was used. Polycarbonate is a layer of compact disc (CD) structure which considered dye immobilized on its surface and have reading and writing abilities of information via 0,1 bites. In this study, surfaces of polycarbonate modified by the mixture of 5% sulfuric acid and 20% acetic acid; furthermore, by using of PEI as cationic resin the surface of polycarbonate was charged and BR immobilized on it electrostatically. The modified surfaces were characterized by AFM technique. Also, light activity for reading data is retained. This is an appropriate method for optimal stability and activity assay of the protein and also is suitable for preparation of protein memories.