Functional Interfacing of Rhodospirillum rubrum Chromatophores to a Conducting Support for Capture and Conversion of Solar Energy (original) (raw)
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The Journal of Physical Chemistry B, 2013
Owing to the considerable current interest in replacing fossil fuels with solar radiation as a clean, renewable, and secure energy source, light-driven electron transport in natural photosynthetic systems offers a valuable blueprint for conversion of sunlight to useful energy forms. In particular, intracytoplasmic membrane vesicles (chromatophores) from the purple bacterium Rhodospirillum rubrum provide a fully functional and robust photosynthetic apparatus, ideal for biophysical investigations of energy transduction and incorporation into biohybrid photoelectrochemical devices. These vesicular organelles, which arise by invagination of the cytoplasmic membrane, are the sites of the photochemical reaction centers and the light harvesting 1 (LH1) complex. The LH1 protein is responsible for collecting visible and near-IR radiant energy and funneling these excitations to the reaction center for conversion into a transmembrane charge separation. Here, we have investigated the morphology, fluorescence kinetics and photocurrent generation of chromatophores from Rsp. rubrum deposited directly onto gold surfaces in the absence of chemical surface modifications. Atomic force microscopy showed a significant coverage of the gold electrode surface by Rsp. rubrum chromatophores. By in situ fluorescence induction/relaxation measurements, a high retention of the quantum yield of photochemistry was demonstrated in the photoactive films. Chronoamperometric measurements showed that the assembled bioelectrodes were capable of generating sustained photocurrent under white light illumination at 220 mW/cm 2 with a maximum current of 1.5 μA/cm 2 , which slowly declines in about 1 week. This study demonstrates the possibility of photoelectrochemical control of robust chromatophore preparations from Rsp. rubrum that paves the way for future incorporation into functional solar cells.
Photoelectrochemical cells based on photosynthetic systems: a review
Biofuel Research Journal, 2015
Photobioelectrochemical photoconverters based on photosynthetic systems are discussed Strategies used to improve the efficiency of photobioelectrochemical cells were presented Advantages and disadvantages of photobioelectrochemical cells were highlighted GRAPHICAL ABSTRACT ARTICLE INFO ABSTRACT Article history:
Near‐IR Absorbing Solar Cell Sensitized With Bacterial Photosynthetic Membranes
Photochemistry and …, 2012
Current interest in natural photosynthesis as a blueprint for solar energy conversion has led to the development of a biohybrid photovoltaic cell in which bacterial photosynthetic membrane vesicles (chromatophores) have been adsorbed to a gold electrode surface in conjunction with biological electrolytes (quinone [Q] and cytochrome c; Magis et al.
Biochimica et Biophysica Acta (BBA) - Bioenergetics, 1982
Chromatophore and sphericle vesicles, isolated from the photosynthetic bacterium, Rhodopseudomonas sphaeroldes R-26, were dried as a film on tin oxide electrodes, and their response to red light was examined in a liquid-junction, photoelectrochemical cell. Steady-state photocurrents demonstrate that electron transfer must occur across both the SnO 2/chromatophore interlace and the chromatophore film itself. The photoelectrochemical cell functions only when the chromatophore quinone pool is oxidized and cytochrome c 2 is reduced. Proton transport is not involved. Coated SnO 2 electrodes act as photocathodes instead of photoanodes, which is the case for uncoated SnO 2. The addition of electron carriers to photoelectrochemical cells incorporating chromatophore-and sphericle-coated electrodes suggest that factors other than the orientation of the reaction center within the vesicle membrane play an important part in governing the net electrical responses. A model is proposed to explain how electron transport occurs across a vesicle-coated electrode.
“Garnishing” the photosynthetic bacterial reaction center for bioelectronics
J. Mater. Chem. C, 2015
The photosynthetic reaction center is an extraordinarily efficient natural photoconverter, which can be ideally used in combination with conducting or semiconducting interfaces to produce electrical signals in response to absorption of photons. The actual applicability of this protein in bioelectronic devices critically depends on the finding of (a) suitable deposition methods enabling controlled addressing and precise orientation of the protein on electrode interfaces and (b) chemical manipulation protocols able to tune and enhance protein light absorption in specific or broader spectral regions. Literature reports several examples of approaches to fulfill these requirements, which have faced in different ways the fundamental issues of assembling the biological component and non-natural systems, such as electrode surfaces and artificial light harvesting components. Here we present a short overview of the main methods reported to accomplish both the objectives by properly ''garnishing'' the photosynthetic reaction center (RC) via chemical modifications.
Photosynthetic apparatus of Rhodobacter sphaeroides exhibits prolonged charge storage
Nature Communications, 2019
Photosynthetic proteins have been extensively researched for solar energy harvesting. Though the light-harvesting and charge-separation functions of these proteins have been studied in depth, their potential as charge storage systems has not been investigated to the best of our knowledge. Here, we report prolonged storage of electrical charge in multilayers of photoproteins isolated from Rhodobacter sphaeroides. Direct evidence for charge build-up within protein multilayers upon photoexcitation and external injection is obtained by Kelvinprobe and scanning-capacitance microscopies. Use of these proteins is key to realizing a 'selfcharging biophotonic device' that not only harvests light and photo-generates charges but also stores them. In strong correlation with the microscopic evidence, the phenomenon of prolonged charge storage is also observed in primitive power cells constructed from the purple bacterial photoproteins. The proof-of-concept power cells generated a photovoltage as high as 0.45 V, and stored charge effectively for tens of minutes with a capacitance ranging from 0.1 to 0.2 F m −2 .
Photosystem I – Based biohybrid photoelectrochemical cells
Bioresource Technology, 2010
Photosynthesis is the process by which Nature coordinates a tandem of protein complexes of impressive complexity that function to harness staggering amounts of solar energy on a global scale. Advances in biochemistry and nanotechnology have provided tools to isolate and manipulate the individual components of this process, thus opening a door to a new class of highly functional and vastly abundant biological resources. Here we show how one of these components, Photosystem I (PSI), is incorporated into an electrochemical system to yield a stand-alone biohybrid photoelectrochemical cell that converts light energy into electrical energy. The cells make use of a dense multilayer of PSI complexes assembled on the surface of the cathode to produce a photocatalytic effect that generates photocurrent densities of 2lA/cm2atmoderatelightintensities.WedescribetherelationshipbetweenthecurrentandvoltageproductionofthecellsandthephotoinducedinteractionsofPSIcomplexeswithelectrochemicalmediators,andshowthattheperformanceofthepresentdeviceislimitedbydiffusionaltransportoftheelectrochemicalmediatorsthroughtheelectrolyte.Thesebiohybriddevicesdisplayremarkablestability,astheyremainactiveinambientconditionsforatleast280days.Evenatbench−scaleproduction,thematerialsrequiredtofabricatethecellsdescribedinthismanuscriptcost2 lA/cm 2 at moderate light intensities. We describe the relationship between the current and voltage production of the cells and the photoinduced interactions of PSI complexes with electrochemical mediators, and show that the performance of the present device is limited by diffusional transport of the electrochemical mediators through the electrolyte. These biohybrid devices display remarkable stability, as they remain active in ambient conditions for at least 280 days. Even at bench-scale production, the materials required to fabricate the cells described in this manuscript cost 2lA/cm2atmoderatelightintensities.WedescribetherelationshipbetweenthecurrentandvoltageproductionofthecellsandthephotoinducedinteractionsofPSIcomplexeswithelectrochemicalmediators,andshowthattheperformanceofthepresentdeviceislimitedbydiffusionaltransportoftheelectrochemicalmediatorsthroughtheelectrolyte.Thesebiohybriddevicesdisplayremarkablestability,astheyremainactiveinambientconditionsforatleast280days.Evenatbench−scaleproduction,thematerialsrequiredtofabricatethecellsdescribedinthismanuscriptcost10 cents per cm 2 of active electrode area.
Improving the stability of photosystem I–based bioelectrodes for solar energy conversion
Current Opinion in Electrochemistry, 2019
Isolated photosystem I (PSI) has been integrated into numerous technologies for solar energy conversion. Interest in PSI is a consequence of its high internal quantum efficiency, thermal stability, ease of extraction, and adaptability. While there has been success in improving performance to elevate PSI biohybrid technologies toward a practical realm, the stability of PSI bioelectrodes is also of critical importance. Commercial solar energy conversion technologies are expected to achieve lifetimes of the order of ten years; however, many research-scale PSI bioelectrodes have only been tested for tens of days. Key areas affecting PSI bioelectrode stability include the effects of reactive oxygen species, immobilization strategies, and the environment within solid-state PSI biohybrid photovoltaics. At the current state, further investigation of long-term stability is necessary in enabling the development of PSI bioelectrodes for both photoelectrochemical cells and solid-state biohybrid photovoltaics.
Photosynthetic reaction center-functionalized electrodes for photo-bioelectrochemical cells
Photosynthesis Research, 2014
During the last few years, intensive research efforts have been directed toward the application of several highly efficient light-harvesting photosynthetic proteins, including reaction centers (RCs), photosystem I (PSI), and photosystem II (PSII), as key components in the light-triggered generation of fuels or electrical power. This review highlights recent advances for the nano-engineering of photobioelectrochemical cells through the assembly of the photosynthetic proteins on electrode surfaces. Various strategies to immobilize the photosynthetic complexes on conductive surfaces and different methodologies to electrically wire them with the electrode supports are presented. The different photoelectrochemical systems exhibit a wide range of photocurrent intensities and power outputs that sharply depend on the nano-engineering strategy and the electroactive components. Such cells are promising candidates for a future production of biologically-driven solar power.