Nano-hairpin probe successfully measures electrical activity of cells

London, Aug 13 (ANI): Scientists have succeeded in using a nanometre-scale probe disguised as part of a biological membrane to infiltrate and monitor a living cell.

And researchers hope that the lipid-coated device will reveal more about the inner workings of cells.

The most common device currently used to record electrical signals within neurons and other cells is made from a micrometre-scale glass pipette containing an electrode.

The pipette 'clamps' onto the cell's membrane and records electrical signals, but the technique is far from ideal, said Charles Lieber, a chemist at Harvard University in Cambridge, Massachusetts.

The pipette is cumbersome, and often damages the cell it is meant to monitor.

The researchers wanted to make a nanometre-scale device incorporating a transistor that would be able to enter a cell and take electrical readings without causing too much harm.

The team could build a more compact device by using a nanometre-scale wire shaped into a hairpin.

The business end of the transistor sits on the pin's bent tip and penetrates the cell.

The two arms of the hairpin, which serve as electrical contacts, do not penetrate the cell deeply so minimise damage.

The smallest nanoprobe made by the team was less than 50 nanometres wide - smaller than the diameter of many virus particles.

"This is literally the scale of the inner components of a cell," Nature quoted Lieber as saying.

Unlike the pipette device, which required additional equipment to amplify the electrical signal, the transistor can scale-up signals that it measures, allowing "exquisite sensitivity", he said.

The team demonstrated that the nanoprobe works by poking it into a single cultured embryonic chicken heart cell and recording a series of voltage peaks with a frequency of 2.3 Hertz, corresponding to the beating of the cell2. (ANI)