Device to decipher nerve signal transmissions
doi:10.1038/nindia.2018.124 Published online 25 September 2018
Physicists have designed an electrochemical diode and transistor that shows excellent potential for controlling and modulating current1. The contraption could be used to make a wide range of electronic devices including one that can shed light on transport of hydrogen ions in neurons.
Unlike graphene-based solid-state diodes, liquid-state diodes running on electrolytes are not common. Scientists from the Saha Institute of Nuclear Physics and the Indian Institute of Science Education and Research in Kolkata, India, invented the electrochemical diode and transistor by using two dissimilar materials: chemically synthesized graphene oxide and electrochemically reduced graphene oxide.
The researchers, led by Sangam Banerjee, then explored the potential of the device to control and modulate current in the presence of aqueous electrolyte and an external voltage.
When exposed to the electrolyte and external voltage, the device was able to generate ions through oxidation and reduction that, in turn, created ionic current – a characteristic feature of a diode. The device also showed efficiency in controlling and rectifying (converting alternating current to direct current) the ionic current by modulating the charge carriers at the interface of the device and the electrolyte.
Since this device has the potential to generate ions by splitting water, it could be used to make hydrogen fuel. With this device, it is possible to study the transport of hydrogen and hydroxyl ions in water.
“This device could also shed light on the transport of hydrogen ions in neurons through a process known as proton hopping. This is one of the key processes that help send signals through the nerve cells,” says Banerjee.
1. Jana, S. K. et al. Rectification and amplification of ionic current in planar graphene/graphene-oxide junctions: an electrochemical diode and transistor. J. Phys. Chem. C. 122, 11378-11384 (2018)