Navigation Links
Rice scientists make breakthrough in single-molecule sensing
Date:2/6/2008

HOUSTON, Feb. 6, 2008 -- In a study that could lay the foundation for mass-produced single-molecule sensors, physicists and engineers at Rice University have demonstrated a means of simultaneously making optical and electronic measurements of the same molecule.

The research, which is available online, is slated to appear in an upcoming issue of the journal Nano Letters. The experiments were performed on a nanoelectronic device consisting to two tiny electrodes separated by a molecule-sized gap. Using electric current, the researchers measured conduction through single molecules in the gap. In addition, light-focusing properties of the electrodes allowed the researchers to identify the molecule by a unique optical fingerprint.

"We can mass-produce these in known locations, and they have single-molecule sensitivity at room temperature in open air," said study co-author Douglas Natelson, associate professor of physics and astronomy and co-director of Rice's Quantum Magnetism Laboratory (QML). "In principle, we think the design may allow us to observe chemical reactions at the single-molecule level."

While scientists have used electronic and optical instruments to measure single molecules before, Rice's system is the first that allows both simultaneously -- a process known as "multimodal" sensing -- on a single small molecule.

The research sprang from a collaboration between Natelson's group -- where the electrodes were developed -- and Rice's Laboratory for Nanophotonics (LANP), where the simultaneous electronic and optical testing was performed. In research published last year, the two groups explained how the electrodes focus near-infrared light into the molecule-sized gap, increasing light intensity in the gap by as much as a million times. The increased intensity allows the team to collect unique optical signatures for molecules trapped there via a technique called surface enhanced Raman spectroscopy (SERS).

"Our latest results confirm that we have the sensitivity required to measure single molecules," said LANP Director Naomi Halas, the Stanley C. Moore Professor of Electrical and Computer Engineering and professor of chemistry. "That sensitivity, and the multimodal capabilities of this system, gives us a great tool for fundamental science at the nanoscale."

Daniel Ward, a student in Natelson's research group, built the electrodes from tiny gold wires on silicon wafers and performed the critical measurements. The group specializes in studying the electronic and magnetic properties of nanoscale objects -- particles and devices that are built with atomic precision. The devices are so small they can only be seen with certain types of microscopes, and even those provide unclear pictures at best. Natelson said the new multimodal device gives researchers a much clearer idea of what is going on by combining two different kinds of measurements, electronic and optical.

"Conduction across our electrodes is known to depend on a quantum effect called 'tunneling,'" Natelson said. "The gaps are so small that only one or two molecules contribute to the conduction. So when we get conduction, and we see the optical fingerprint associated with a particular molecule, and they track each other, then we know we're measuring a single molecule and we know what kind of molecule it is. We can even tell when it rotates and changes position."


'/>"/>

Contact: Jade Boyd
jadeboyd@rice.edu
713-348-6778
Rice University
Source:Eurekalert  

Related biology news :

1. Carnegie Mellon scientists develop fluorescent proteins for live cell imaging, biosensor design
2. Scientists obtain core samples from subsea fault system off Japan
3. Scientists discover new species of giant elephant-shrew
4. Scientists outline novel approach to ecosystem management
5. Scientists achieve major genetics breakthrough
6. In nature -- and maybe the corner office -- scientists find that generalists can thrive
7. Using DNA, scientists hunt for the roots of the modern potato
8. Ecologists, material scientists pursue genetics of diatoms elegant, etched casing
9. In diatom, scientists find genes that may level engineering hurdle
10. Scientists call for urgent research into real impacts of invasive species
11. Scientists discover a new player in innate immune response
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Rice scientists make breakthrough in single-molecule sensing
(Date:1/6/2017)... , Jan. 5, 2017  Delta ID Inc., a ... scanning technology for automotive at CES® 2017. Delta ID ... ) to demonstrate the use of iris scanning as ... authenticate the driver in a car, and as a ... driving experience. Delta ID and Gentex will ...
(Date:12/22/2016)... 2016  As part of its longstanding mission to improve ... company, recently released its latest children,s book, titled ... on the topics of inheritance and variation of traits that ... in elementary school classrooms in the US. ... Ariana Killoran , whose previous book with 23andMe, ...
(Date:12/19/2016)... y TORONTO , 19 de diciembre de 2016 ... Inc. que permitirá el desarrollo acelerado de MSC-1, un anticuerpo humanizado ... tipos de tumor en 2017, con múltiples sitios previstos a lo ... ... objetivo en el factor inhibidor de leucemia (LIF), una citoquina pleiotrópica ...
Breaking Biology News(10 mins):
(Date:1/24/2017)... 23, 2017  Today, the Fisher Center for Alzheimer,s ... an important study that could lead to the development ... Alzheimer,s disease. This groundbreaking research was conducted by the ... Nobel Laureate Dr. Paul Greengard , in the ... Fisher Center scientists have linked a mutation that ...
(Date:1/23/2017)... , Jan. 23, 2017  Spherix Incorporated (Nasdaq: ... to the fostering of technology and monetization of intellectual ... infringement lawsuits. Anthony Hayes , Chief ... we will continue to communicate with shareholders about the ... our due diligence on other patent assets that fit ...
(Date:1/23/2017)... , January 23, 2017 Atlas ... announces completion of its Series D financing, raising $35 million ... new investor, Wondfo Biotech. ... Development of the Atlas Genetics io® system ... Chlamydia trachomatis (CT) test announced in February 2016.  This new ...
(Date:1/23/2017)... , ... January 23, 2017 , ... ... at the Caribbean Neurosciences Symposium (CANS) annual meeting in Montego Bay, Jamaica from ... and host a hands-on workshop for surgeons to experience the simplicity of the ...
Breaking Biology Technology: