Tiny Nanowire Probes Measure Intracellular Electrical Activity

Researchers at the University of Surrey and Harvard University have developed tiny nanoprobes that can measure electrical signals inside cells, such as neurons and cardiac cells. Unlike previous technology for intracellular electrophysiology, the nanoprobes cause minimal destruction to the cells, and could pave the way for human-machine interfaces such as neural prosthetics.

Measuring electrical activity in cells has a variety of uses and applications, from research and diagnostics to advanced human-machine interfaces. Current techniques to measure these signals, such as patch clamp techniques, can cause damage to the cell membrane, thereby killing the cell being assessed. This isn’t ideal, as it makes long-term applications, such as neural prostheses, difficult or impossible.

In an effort to create something less invasive, these researchers have developed a nanowire array, consisting of U-shaped transistor probes. The probes are flexible, and have the potential to measure multiple signals simultaneously. So far, the researchers have used them to obtain clear readings from neurons and other electrogenic cells. By optimizing the device size and shape, the team’s probes can effectively penetrate the cells to get the best possible signal.

“Our ultra-small, flexible, nanowire probes could be a very powerful tool as they can measure intracellular signals with amplitudes comparable with those measured with patch clamp techniques; with the advantage of the device being scalable, it causes less discomfort and no fatal damage to the cell,” said Yunlong Zhao, a researcher involved in the study. “Through this work, we found clear evidence for how both size and curvature affect device internalization and intracellular recording signal.”

The nanoprobes are 100 times smaller than the next smallest comparable technology, and can be scaled to suit a variety of devices and applications. “This work represents a major step towards tackling the general problem of integrating ‘synthesized’ nanoscale building blocks into chip and wafer scale arrays, and thereby allowing us to address the long-standing challenge of scalable intracellular recording,” said Professor Charles Lieber, another researcher involved in the study. “In the longer term, we see these probe developments adding to our capabilities that ultimately drive advanced high-resolution brain-machine interfaces and perhaps eventually bringing cyborgs to reality.”

Study in Nature Nanotechnology: Scalable ultrasmall three-dimensional nanowire transistor probes for intracellular recording

Via: University of Surrey