Featured Research

from universities, journals, and other organizations

New nanoscale transistors allow sensitive probing inside cells

Date:
August 13, 2010
Source:
Harvard University
Summary:
Chemists and engineers have fashioned nanowires into a new type of V-shaped transistor small enough to be used for sensitive probing of the interior of cells. The new device is smaller than many viruses and about one-hundredth the width of the probes now used to take cellular measurements, which can be nearly as large as the cells themselves.

Chemists and engineers at Harvard University have fashioned nanowires into a new type of V-shaped transistor small enough to be used for sensitive probing of the interior of cells.

The new device, described in the journal Science, is smaller than many viruses and about one-hundredth the width of the probes now used to take cellular measurements, which can be nearly as large as the cells themselves. Its slenderness is a marked improvement over these bulkier probes, which can damage cells upon insertion, reducing the accuracy or reliability of any data gained.

"Our use of these nanoscale field-effect transistors, or nanoFETs, represents the first totally new approach to intracellular studies in decades, as well as the first measurement of the inside of a cell with a semiconductor device," says senior author Charles M. Lieber, the Mark Hyman, Jr. Professor of Chemistry at Harvard. "The nanoFETs are the first new electrical measurement tool for intracellular studies since the 1960s, during which time electronics have advanced considerably."

Lieber and colleagues say nanoFETs could be used to measure ion flux or electrical signals in cells, particularly neurons. The devices could also be fitted with receptors or ligands to probe for the presence of individual biochemicals within a cell.

Human cells can range in size from about 10 microns (millionths of a meter) for nerve cells to 50 microns for cardiac cells. While current probes measure up to 5 microns in diameter, nanoFETs are several orders of magnitude smaller: less than 50 nanometers (billionths of a meter) in total size, with the nanowire probe itself measuring just 15 nanometers in diameter.

Aside from their small size, two features allow for easy insertion of nanoFETs into cells. First, Lieber and colleagues found that by coating the structures with a phospholipid bilayer -- the same material cell membranes are made of -- the devices are easily pulled into a cell via membrane fusion, a process related to that used to engulf viruses and bacteria.

"This eliminates the need to push the nanoFETs into a cell, since they are essentially fused with the cell membrane by the cell's own machinery," Lieber says. "This also means insertion of nanoFETs is not nearly as traumatic to the cell as current electrical probes. We found that nanoFETs can be inserted and removed from a cell multiple times without any discernible damage to the cell. We can even use them to measure continu-ously as the device enters and exits the cell."

Secondly, the current paper builds upon previous work by Lieber's group to introduce triangular "stereocenters" -- essentially, fixed 120 joints -- into nanowires, structures that had previously been rigidly linear. These stereocenters, analogous to the chemical hubs found in many complex organic molecules, introduce kinks into 1-D nanostructures, transforming them into more complex forms.

Lieber and his co-authors found that introducing two 120 angles into a nanowire in the proper cis orientation creates a single V-shaped 60 angle, perfect for a two-pronged nanoFET with a sensor at the tip of the V. The two arms can then be connected to wires to create a current through the nanoscale transistor.

Lieber's co-authors on the Science paper are Bozhi Tian, Tzahi Cohen-Karni, Quan Qing, Xiaojie Duan, and Ping Xie, all of Harvard's Department of Chemistry and Chemical Biology and School of Engineering and Applied Sciences. The work was sponsored by the National Institutes of Health and the McKnight Foundation for Neuroscience.


Story Source:

The above story is based on materials provided by Harvard University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Tian et al. Three-Dimensional, Flexible Nanoscale Field-Effect Transistors as Localized Bioprobes. Science, 2010; 329 (5993): 830 DOI: 10.1126/science.1192033

Cite This Page:

Harvard University. "New nanoscale transistors allow sensitive probing inside cells." ScienceDaily. ScienceDaily, 13 August 2010. <www.sciencedaily.com/releases/2010/08/100812151626.htm>.
Harvard University. (2010, August 13). New nanoscale transistors allow sensitive probing inside cells. ScienceDaily. Retrieved August 30, 2014 from www.sciencedaily.com/releases/2010/08/100812151626.htm
Harvard University. "New nanoscale transistors allow sensitive probing inside cells." ScienceDaily. www.sciencedaily.com/releases/2010/08/100812151626.htm (accessed August 30, 2014).

Share This




More Plants & Animals News

Saturday, August 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Raw: Australian Sheep Gets Long Overdue Haircut

Raw: Australian Sheep Gets Long Overdue Haircut

AP (Aug. 28, 2014) Hoping to break the record for world's wooliest, Shaun the sheep came up 10 pounds shy with his fleece weighing over 50 pounds after being shorn for the first time in years. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Minds Blown: Scientists Develop Fish That Walk On Land

Minds Blown: Scientists Develop Fish That Walk On Land

Newsy (Aug. 28, 2014) Canadian scientists looking into the very first land animals took a fish out of water and forced it to walk. Video provided by Newsy
Powered by NewsLook.com
Huge Ancient Wine Cellar Found In Israel

Huge Ancient Wine Cellar Found In Israel

Newsy (Aug. 28, 2014) An international team uncovered a large ancient wine celler that likely belonged to a Cannonite ruler. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins