Photocurrent Generation from Thylakoid Membranes on Osmium‐Redox‐Polymer‐Modified Electrodes

Abstract

Thylakoid membranes (TMs) are uniquely suited for photosynthesis owing to their distinctive structure and composition. Substantial efforts have been directed towards use of isolated photosynthetic reaction centers (PRCs) for solar energy harvesting, however, few studies investigate the communication between whole TMs and electrode surfaces, due to their complex structure. Here we report on a promising approach to generate photosynthesis-derived bioelectricity upon illumination of TMs wired with an osmium-redox-polymer modified graphite electrode, and generate a photocurrent density of 42.4 μA cm(-2).

Hybrid bio-photo-electro-chemical cells for solar water splitting

“…reported the production of an unmediated photocurrent density of 16 μA cm −2 using crude Synechocystis membranes and N-acetyl cysteine-modified gold electrode. A photocurrent density of 42 μA cm −2 was reported by Hamidi et al 22,. using immobilized spinach thylakoids in osmium polymer network on a graphite electrode.…”

“…Hence, the photocurrent density reported here sets a new record for solar-simulated measurements of BPEC cells utilizing any photosynthetic membranes, crude or purified ones. Furthermore, the preparation of isolated reaction centers is expensive, time and energy consuming and requires the use of polluting detergents, and the photocurrent quickly decays due to irreversible degradation of the reaction centers1316181922. Our approach alleviates these drawbacks by using crude thylakoids that can be readily replaced by fresh ones, as demonstrated below.…”

The ins and outs of microorganism–electrode electron transfer reactions

“…In addition to modifying electrode surfaces, use of redox and/or conducting polymers [90][91] and/or nanomaterials could also be explored to electrically wire microorganisms to electrodes, including connecting metabolic processes inside cells to electrodes outside cells in a manner analogous to that used to wire redox enzymes to electrode surfaces [92][93] . This is an under-exploited approach to engineering microbial BES which may expand the scope of useable microorganisms to those with interesting/useful catalytic properties but that lack ability to electrically wire themselves to electrodes [94][95] .…”

“…In addition to modifying electrode surfaces, use of redox and/or conducting polymers [90][91] and/or nanomaterials could also be explored to electrically wire microorganisms to electrodes, including connecting metabolic processes inside cells to electrodes outside cells in a manner analogous to that used to wire redox enzymes to electrode surfaces [92][93] . This is an under-exploited approach to engineering microbial BES which may expand the scope of useable microorganisms to those with interesting/useful catalytic properties but that lack ability to electrically wire themselves to electrodes [94][95] .Although the EET mechanisms may be different, surface modifications that promote biofilm formation on anodes tend to benefit biofilm formation on cathodes as well. For instance, introduction of positive charged functional groups at carbon cloth electrodes significantly improves formation and performance of Sporomusa ovate films used for electrosynthetic production of acetate in a microbial electrolysis cell [96][97] .…”

Electrocatalytic Mechanism Involving Michaelis–Menten Kinetics at the Preparative Scale: Theory and Applicability to Photocurrents from a Photosynthetic Algae Suspension With Quinones

“…[8] In this way,i solated thylakoid membranes can also be involved and immobilized at the workinge lectrode. [9][10][11][12][13] Al ong-term approachi so bviously to work with intact photosynthetic organisms (algae, cyanobacteria, …). [14][15][16] In this case, culture and proliferationo ft he photosynthetic cells is expecteda nd ensure the stabilityo ft he bioelectricity production.…”