Researchers Hope To Create Nanowire Cancer Detectors
March 8, 2008 7:57 PM
comment(s) - last by
Bottom-up approach used to fabricate nanowire (NW) resonator arrays. In step a) the probe molecules attach to the NW. In b) the nanowires are suspended in holes of photoresist. In c) add'l photoresist is applied sandwich the NW's in. In d) the resist is etched and melted is added to mount the NW. Finally in e) The detection is tested.
(Source: Penn State and Nature Nanotechnology)
An array of nanowires. Note the small grey 20 micron bar on the lower left. The nanowires have a diameter of approximately 300 nm and are visible as the small extensions from the white blobs (which are the metal mounts to the chip).
(Source: Penn State)
Chalk up another promising application of nanotechnology
Nanowires, nanoscale wires of organic or semiconductors material, are a
hot new field of research
due to their
. Now researchers are looking to put the tiny wires to a new use -- in medical sensing.
A team at Penn State University has come up with a
new bottom-up approach to help make attaching nanowires to a chip easier
. Such nanowires, with attached sensor molecules could create detectors such as "diving board resonators" which would monitor minute changes in resonance based on molecules bound to the sensor molecules at their tips. Such chemical sensors could be used to create integrated detectors of cancer or other diseases, which emit chemical markers.
Rustom B. Bhiladvala, research assistant professor, electrical engineering who helped conduct the research describe the process stating, "Diagnostic chips can be made more useful by assembling, at predetermined locations on the chip, large numbers of nanowires pretreated off chip. Using this new bottom-up method, our group has demonstrated that thousands of single wires can be successfully aligned and anchored to form tiny diving board resonator arrays."
The traditional top-down approach to designing resonators is more uniform than the new approach but also more limited. In this approach nanoresonators are carved from base silicon. Changes in the materials and the addition of chemical sensors must occur after these nanoresonators have been carved. The varieties of molecules available for chemical sensors are also limited by the base materials.
The bottom-up approach involves attaching nanowires to a premade chip, through the use of photoresist and electrical current. Such an approach takes advantage of self-assembly similar to that
used to assemble a CMOS chip
, previously detailed at
. Each bottom up chip is unique, but by controlling the nanowire solution, material used in the nanowires, and the current applied, similar chips can be made.
Advantages of the nanowires method are that the wires can be attached to any location on the chip desired. The wires can also feature a broader assortment of organic or inorganic materials and feature more types of probe molecules, which could be leveraged to make new, cutting-edge sensors.
Theresa S. Mayer, professor of electrical engineering, explains these advantages and disadvantages, stating, "We can achieve high device integration yields, but the devices are not as uniform as top-down manufactured devices. However, we can access materials that are not easy to integrate into the devices with top-down methods. We can also integrate wires treated off-chip with entirely different probe molecules that are attached to the wires using condition optimized for that molecule."
The team used the new bottom-up approach to fabricate a proof-of-concept chip using a resonator array of single-crystal silicon or polycrystalline rhodium nanowires -- rhodium is a metal similar to platinum,
also used in quantum computing
. The chips could detect molecules based on vibrations created when the molecules bound to the probe-tips of the nanowires.
The measurements required a partial vacuum to negate the effects of air dampening. However the sensor was able to operate at pressures of up to a thousandth of an atmosphere, which are achievable by small inexpensive pumps. This easy solution raises the technology's promise to the medical industry.
Meyer acknowledges that the approach is very new, but sees the approach as eventually being adopted for commercial medical sensors. She states, "Bottom-up fabrication is an entirely new nanomanufacturing approach and we need to create devices that have properties that match what we can now make using top-down fabrication. Our vision is to make large arrays of nano size devices with multiple probes for multiple targets by placing different groups of functionalized nanowires sequentially on chips."
The group's research
appears in the current issue of
This article is over a month old, voting and posting comments is disabled
3/9/2008 6:31:46 PM
in the face
"Vista runs on Atom ... It's just no one uses it". -- Intel CEO Paul Otellini
Quantum Computer Researchers Store "Sub Zero" Light Vacuum
March 7, 2008, 9:31 PM
Scientists Design 1GHz CMOS Circuit Using Carbon Nanotubes
February 15, 2008, 3:10 PM
Using Nanowire Silicon Thermoelectrics to Capture Waste Heat
January 21, 2008, 3:17 AM
New "Solar" Nanowires: Cheap and Durable
October 25, 2007, 2:50 PM
Implatantable Nanogenerator Turns Blood Flow Into Electricity
July 25, 2007, 12:31 PM
Newly Discovered Costa Rican Glass Frog is Kermit's Doppelgänger
April 22, 2015, 11:26 AM
Researchers Hope to Find "Exotic" Lifeforms Inside Crater of Dinosaur Killing Meteor
April 14, 2015, 8:47 PM
Mathematician's Sociological Formulation May Explain the "Hipster Paradox"
April 14, 2015, 1:13 PM
Cool Science Video: This is What a McDonald's Burger Looks Like in Your Stomach
April 7, 2015, 1:43 PM
Fraud Artist Engineered Stunning UK Jailbreak Via Typosquatting, Email
April 4, 2015, 2:57 PM
Food Chemists at Italy's Barilla Claim to Have Perfect Instant Noodles w/out Frying
March 26, 2015, 4:25 PM
Most Popular Articles
Windows 10 Build 10061: A Quick Review
April 27, 2015, 10:57 AM
Microsoft "Welcomes Developers" to Its New "Edge Browser" (Codename: Spartan)
April 29, 2015, 7:25 PM
Worst Kept Secret -- $35 Million Anonymous Sharing App Startup Shuts Down
April 30, 2015, 7:33 AM
Leather-Bound LG G4 Shuffles Out, "Specially Designed" Snapdragon 808 SoC
April 28, 2015, 4:00 PM
Report: Apple Pulls the Plug on Apple Watch Store Launch
April 16, 2015, 3:18 PM
Latest Blog Posts
Sceptre Airs 27", 120 Hz. 1080p Monitor/HDTV w/ 5 ms Response Time for $220
Dec 3, 2014, 10:32 PM
Costco Gives Employees Thanksgiving Off; Wal-Mart Leads "Black Thursday" Charge
Oct 29, 2014, 9:57 PM
"Bear Selfies" Fad Could Turn Deadly, Warn Nevada Wildlife Officials
Oct 28, 2014, 12:00 PM
The Surface Mini That Was Never Released Gets "Hands On" Treatment
Sep 26, 2014, 8:22 AM
ISIS Imposes Ban on Teaching Evolution in Iraq
Sep 17, 2014, 5:22 PM
More Blog Posts
Copyright 2015 DailyTech LLC. -
Terms, Conditions & Privacy Information