A team of researchers led by Ryuhei Nakamura of the RIKEN Center for Sustainable Resource Science (CSRS) in Japan and fromEarth-Life Science Institute (ELSI) of the Tokyo Institute of Technology has discovery inorganic nanostructures around hydrothermal vents in the deep ocean that are strikingly similar to the molecules that make life as we know it possible.
Inorganic nanostructures and their organization
These nanostructures organize themselves autonomously and act as selective ion channelscreating energy that can be harnessed in the form of electricity; published on September 25th on Nature Communicationsthe findings influence not only our understanding of how life began, but they can also be applied to industrial harvesting of blue energy.
When seawater seeps deep into the Earth through cracks on the ocean floor, it is heated by magma, it rises to the surface and is released into the ocean through fissures called hydrothermal vents.
Upwelling warm water contains dissolved minerals acquired during its journey deep into the Earth, and when it encounters cold ocean water, chemical reactions cause the mineral ions to rush out of the water, forming solid structures around the mouth, called fall.
The hydrothermal vents they are considered the birthplace of life on Earth because they provide the necessary conditions: they are stable, rich in minerals and contain sources of energy and much of life on Earth depends on osmotic energy, which is created by ionic gradients (unlike in concentration of salt and protons) between the inside and outside of living cells.
RIKEN CSRS researchers were studying hydrothermal vents hosted by serpentinites, as this type of vent presents mineral precipitates with a very complex layered structure, formed by metal oxides, hydroxides and carbonates. “Unexpectedly, we found that osmotic energy conversion, a vital function in the modern life of plants, animals and microbes, it can occur abiotically in a geological environment“, says Nakamura.
Nanostructures and the Pacific seabed
The researchers were studying samples of these nanostructures collected from the Shinkai Seep field, located in Mariana Trench In the Pacific at a depth of 5743 meters; the key sample was an 84 cm piece composed mainly of brucite; Optical microscopes and scans with micrometer-sized X-ray beams have revealed that crystals of burn they were arranged in continuous columns that acted as nano-channels for mouth fluid.
The researchers noticed that the surface of the precipitate was electrically charged and that the magnitude and direction of the charge (positive or negative) varied along the surface; knowing that structured nanopores with variable charge are distinctive features of osmotic energy conversion, they then tested whether such conversion occurred naturally in deep-sea inorganic rock.
The scientific team of RIKEN used an electrode to record the current-voltage of the samples; when the samples were exposed to high concentrations of potassium chloride, the conductivity was proportional to the concentration of salt on the surface of the nanopores.
However at lower concentrations, the conductivity was constant, non-proportional, and determined by the local electrical charge of the precipitate surface and this ionic transport governed by office is very similar to voltage-dependent ion channels observed in living cells, such as neurons.
By testing the samples with chemical gradients that exist in the deep ocean from which they were extracted, the researchers were able to demonstrate that the nanopores act as selective ion channels; in places where carbonate had adhered to the surfacethe nanopores allowed the passage of sodium ions positive. However, in nanopores with calcium adhered to the surface, the pores allowed only negative chloride ions to pass through.
“Spontaneous formation of ion channels discovered in deep-sea hydrothermal vents has direct implications for the origin of life on Earth and beyond“, says Nakamura. “In particular, our study shows how the conversion ofosmotic energya vital function in modern life, can occur abiotically in a geological environment.”
Industrial power plants use salinity gradients between seawater and river water to generate energy, a process called blue energy harvesting; according to Nakamura, understand how the structure of nanopores is generated spontaneously in hydrothermal vents it could help engineers devise better synthetic methods for generating electricity from osmotic conversion.
And what do you think of the discovery and analysis of these new nanostructures by RIKEN and researcher Ryuhei Nakamura? Write it in the comments.
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