Navigation Links
New nanoscale transistors allow sensitive probing inside cells

CAMBRIDGE, Mass. 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 this week 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.


Contact: Michael Patrick Rutter
Harvard University

Related biology technology :

1. Nanoscale silver: No silver lining?
2. New nanoscale process created by UCSB scientists will help computers run faster and more efficiently
3. Nanoscale carbon materials research wins the 2008 Julius Springer Prize for Applied Physics
4. Nanoscale dimensioning is fast, cheap with new NIST optical technique
5. Clemson researchers advance nanoscale electromechanical sensors
6. NIST stress tests probe nanoscale strains in materials
7. Clemson researchers advance nanoscale electromechanical sensors
8. Engineers tune a nanoscale grating structure to trap and release a variety of light waves
9. Models present new view of nanoscale friction
10. New rotors could help develop nanoscale generators
11. Graphene may have advantages over copper for IC interconnects at the nanoscale
Post Your Comments:
Related Image:
New nanoscale transistors allow sensitive probing inside cells
(Date:11/24/2015)... , ... November 24, 2015 , ... Whitehouse Laboratories is ... The new stand-alone facility will be strictly dedicated to basic USP 61, USP ... existing clients the chance to have complete chemistry and micro testing performed by one ...
(Date:11/23/2015)... Nov. 23, 2015 China Cord Blood Corporation ... leading provider of cord blood collection, laboratory testing, hematopoietic ... announced its preliminary unaudited financial results for the second ... September 30, 2015. --> ... , Revenues for the second quarter of fiscal 2016 ...
(Date:11/23/2015)... and PISCATAWAY, New Jersey , ... Crystallographic Data Centre (CCDC) announces the launch ... Database (CSD) and the CSD-System, now complemented by ... CSD-Discovery to support the discovery of new molecules, ... CSD-Enterprise, the complete set of the CCDC,s applications ...
(Date:11/23/2015)... , Nov. 23, 2015  Oxis Biotech, Inc. ... Inc. [OTC: OXIS] and [Euronext Paris: OXI.PA] announced ... Masonic Cancer Center received notification from the U.S. ... proceed with their planned combination Phase 1/Phase 2 ... rights to develop and commercialize OXS-1550, a novel ...
Breaking Biology Technology:
(Date:11/17/2015)... , Nov. 17, 2015  Vigilant Solutions announces ... joined its Board of Directors. --> ... after recently retiring from the partnership at TPG Capital, ... companies with over $140 Billion in revenue.  He founded ... across all the TPG companies, from 1997 to 2013.  ...
(Date:11/12/2015)...   Growing need for low-cost, easy to ... paving the way for use of biochemical sensors ... in clinical, agricultural, environmental, food and defense applications. ... medical applications, however, their adoption is increasing in ... emphasis on improving product quality and growing need ...
(Date:11/9/2015)... Nov. 9, 2015  Synaptics Inc. (NASDAQ: SYNA ... announced broader entry into the automotive market with a ... the pace of consumer electronics human interface innovation. Synaptics, ... ideal for the automotive industry and will be implemented ... Europe , Japan , ...
Breaking Biology News(10 mins):