You can do terrific things with DNA – convicting a murderer, confirming the right father … and building computers! As biomolecular computing is ever-growing, scientists from the University of East Anglia found a new way to convert DNA in a switching mechanism. This could be used in new bio-computers built from DNA.
The structure of DNA is dependent on its surrounding medium. For example, when you add acid to a neutral strand of DNA, it will fold up into a structure known as an ‘i-motif’. When you add a base to the i-motif, it unfolds again. These properties are used as a pH-based switch-on, switch-off system in several nanotechnological applications.
Lead researcher Dr. Zoë Waller and her colleagues have found a new way to further switch the structure of DNA – independently of the pH! As simple as it seems, they used copper salts to fold the DNA and EDTA to unfold it by binding to the copper ions. By using these chemicals, the i-motif can reorganize itself in a so-called ‘hairpin’ structure or go back to its previous i-motif, as illustrated below.The structure of the DNA can not only be changed by pH changes!
Where could such a discovery be applied?
This technique could be used for the detection of copper cations in water, which would be useful since they are highly toxic to fish. But much more thrilling, it provides a potential application in nanotechnology like DNA-based computing!
Zoë Waller develops this idea further: “A potential application of this finding could be to create logic gates for DNA based computing. Logic gates are an elementary building block of digital circuits – used in computers and other electronic equipment. They are traditionally made using diodes or transistors that act as electronic switches. This research expands how DNA could be used as a switching mechanism for a logic gate in DNA-based computing or in nanotechnology.”
DNA-based computing is already a reality, and the field is evolving extremely fast. Did you know that you can store Martin Luther’s Kings I-have-a-dream-speech in DNA? Scientists did this! And in 2013, a first biological transistor was born: the transcriptor.
Built on all the previous discoveries, this new pH-independent switch could improve the future technology of bio-computers.