A group of European scientists has developed a nano-switch touted to provide a link between biological and silicon worlds, with a wide range of possible future uses. From the EU’s CORDIS News Service:
The project itself is rather difficult to conceptualise: a ‘nano-actuator’ device so small that it could be used to move specific DNA fragments, and allow individual DNA sequencing. The project’s aim was to produce an individual molecular ‘nano-switch’…
The researchers used a type of molecular motor known as a ‘Restriction-Modification enzyme’. This molecular motor attaches itself only to specific sequences of A, C, G and T. ‘This binding is very specific, a motor will bind only with its corresponding bases, so you can control exactly where the motor is placed on the vertical DNA strand,’ said Dr Firman.
The DNA strand is held upright by a magnetic field, pulling a magnetic marker at the end of the DNA strand. The molecular motor sits somewhere below the magnetic marker at a specific position, and does not move. When the molecular engine is started, when fed biological fuel ATP, it pulls the DNA strand, stopping when it reaches the magnetic marker.
Why does this matter, and what use is this? Most simply, this nano-switch enables one form of energy to be transferred to another for a useful purpose, and in a controlled fashion. ‘The light switch, the button that makes a retractable pen, all these are actuators, and by developing a molecular switch we’ve created a tiny actuator that could be used in an equally vast number of applications,’ says Dr Firman.
The result is quite literally a building-block for the nano-world, and as the imaginations of researchers grow, so will useful applications of the switch. ‘It could be used as a communicator between the biological and silicon worlds. I could see it providing an interface between muscle and external devices, through its use of ATP, in human implants. Such an application is still 20 or 30 years away,’ says Dr Firman ‘It’s very exciting and right now we’re applying for a patent for the basic concepts.’
One unintended by-product of this research is in DNA sequencing. If the DNA strand is marked with fluorescence, then ‘Knowing the speed of the motor, which is quite reliable and steady at any specific temperature, we could locate the position of the DNA-based Fluor [molecule] relative to the binding site of the motor,’ says Dr Firman. ‘More work needs to be done. However, the concept is sound and we now have enough evidence to indicate that this could be used to sequence single-nucleotide polymorphisms (SNPs) that cause genetic disorders.’