Researchers at the University of Illinois at Urbana-Champaign have developed a needle less than 100 nanometers thick that can be used to deliver molecules into single cells and collect electro-chemical recordings. The group has published its work in Nano Letters.
Over the past 5 years, other groups have unveiled similar nano-needles, but to my knowledge there are two characteristics that make this one superior. Instead of tapering to a point, the needle remains the same width along its entire length, allowing researchers to fully insert it without increasing damage to the cell; It is also capable of delivering single molecules into a cell.
It's this second characteristic that makes the development so exciting and could lead to a whole slew of new ways to investigate cells at the molecular level.
The probe is fashioned from a boron-nitride nanotube and then coated in a thin layer of gold that allowed the researchers to temporarily dock molecules onto the tip. Once inside the environment of the cell, the molecules break free from the gold. Min-Feng Yu, the lead author on the paper, used the needle in his own studies to transfer quantum dots into the cytoplasm of living cells.
He expressed his expectations for the device in an email to me:
"The significance of having such functional electrochemical needle probes is that it is now possible to directly interface with biological system at the cellular level and communicate the intracellular activities with external electronic circuitry. This can then potentially lead to the development of bioelectronics at the individual cell level either for the fundamental study of cell [sic] itself or for controlling or exploiting the complex biological processes in cell for practical sensing or other broad applications."