DNA Tunnelling Detector Embedded in a Nanopore

Researchers from Imperial College London and the LCN have recently performed a breakthrough experiment that could lead to a next generation platform for high throughput DNA sequencing.

The researchers have combined nanotechnology and single molecule techniques to make a device capable of counting the number of nucleotides in a DNA strand, and which could potentially be used to determine the exact sequence. The device consists of a 'nanopore' - a nanometre-scale hole fabricated in an artificial thin membrane - which lies between two tiny platinum electrodes that were delicately constructed on the membrane surface. At such small scales, approaching atomic dimensions, quantum effects are important and a current of electrons can 'tunnel' across the gap between the electrodes. The teams were able to thread a single DNA molecule through the pore and feed it from one side to the other, recording the tunnelling current during the process.

Since the four different DNA nucleotides modulate the tunnelling current in different ways, it is theoretically possible to read the whole genome sequence in one go from a single strand of DNA. Thus this method could prove to be significantly faster and cheaper than current sequencing technology, which requires biochemical amplification and fluorescent labelling of the DNA.

This work has been published in Nano Letters (Aleksandar P. Ivanov, Emanuele Instuli, Catriona McGilvery, Geoff Baldwin, David W. McComb, Tim Albrecht, and Joshua B. Edel, 2010, DOI: 10.1021/nl103873a)

Journal link: http://pubs.acs.org/doi/abs/10.1021/nl103873a

Schematic of the Detector

 
Figure:  Schematic of the Detector