(Image courtesy
Prof. Itamar Willner)
(Jaqnuary 19, 2016) A
new paradigm for the development of photo-bioelectrochemical cells has been
reported in the journal Nature Energy by researchers from The Hebrew University
of Jerusalem, in Israel, and the University of Bochum, in Germany.
The design of photo-bioelectrochemical cells based on native
photosynthetic reaction is attracting substantial recent interest as a means
for the conversion of solar light energy into electrical power.
In the natural photosynthetic apparatus, photosynthetic
reaction is coupled to biocatalytic transformations leading to CO2 fixation and
O2 evolution. Although significant progress has been achieved in the
integration of native photosystems with electrodes for light-to-electrical
energy conversion, the conjugation of the photosystems to enzymes to yield
photo-bioelectrocatalytic solar cells remains a challenge.
Now, researchers report on the construction of
photo-bioelectrochemical cells using the native photosynthetic reaction and the
enzymes glucose oxidase or glucose dehydrogenase. The system consists of modified integrated
electrodes that include the natural photosynthetic reaction center, known as
photosystem I, conjugated to the enzymes glucose oxidase or glucose dehydrogenase. The native proteins are electrically wired by
means of chemical electron transfer mediators.
Photoirradiation of the electrodes leads to the generation of electrical
power, while oxidizing the glucose substrate acting as a fuel.