Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Columbia Engineering and Penn researchers increase speed of single-molecule measurements

19.03.2012
New integrated circuit design could lead to cheaper, faster DNA sequencing

As nanotechnology becomes ever more ubiquitous, researchers are using it to make medical diagnostics smaller, faster, and cheaper, in order to better diagnose diseases, learn more about inherited traits, and more.

But as sensors get smaller, measuring them becomes more difficult—there is always a tradeoff between how long any measurement takes to make and how precise it is. And when a signal is very weak, the tradeoff is especially big.

A team of researchers at Columbia Engineering, led by Electrical Engineering Professor Ken Shepard, together with colleagues at the University of Pennsylvania, has figured out a way to measure nanopores—tiny holes in a thin membrane that can detect single biological molecules such as DNA and proteins—with less error than can be achieved with commercial instruments. They have miniaturized the measurement by designing a custom integrated circuit using commercial semiconductor technology, building the nanopore measurement around the new amplifier chip. Their research will be published in the Advance Online Publication on Nature Methods's website on 18 March at 1400 (2pm) US Eastern time/ 1800 London time.

Nanopores are exciting scientists because they may lead to extremely low-cost and fast DNA sequencing. But the signals from nanopores are very weak, so it is critically important to measure them as cleanly as possible.

"We put a tiny amplifier chip directly into the liquid chamber next to the nanopore, and the signals are so clean that we can see single molecules passing through the pore in only one microsecond," says Jacob Rosenstein, a Ph.D. candidate in electrical engineering at Columbia Engineering and lead author of the paper. "Previously, scientists could only see molecules that stay in the pore for more than 10 microseconds."

Many single-molecule measurements are currently made using optical techniques, which use fluorescent molecules that emit photons at a particular wavelength. But, while fluorescence is very powerful, its major limitation is that each molecule usually produces only a few thousand photons per second. "This means you can't see anything that happens faster than a few milliseconds, because any image you could take would be too dim," explains Shepard, who is Rosenstein's advisor. "On the other hand, if you can use techniques that measure electrons or ions, you can get billions of signals per second. The problem is that for electronic measurements there is no equivalent to a fluorescent wavelength filter, so even though the signal comes through, it is often buried in background noise."

Shepard's group has been interested in single-molecule measurements for several years looking at a variety of novel transduction platforms. They began working with nanopore sensors after Marija Drndic, a professor of physics at the University of Pennsylvania, gave a seminar at Columbia Engineering in 2009. "We saw that nearly everybody else measures nanopores using classical electrophysiology amplifiers, which are mostly optimized for slower measurements," notes Shepard. "So we designed our own integrated circuit instead."

Rosenstein designed the new electronics and did much of the lab work. Drndic's group at the University of Pennsylvania fabricated the nanopores that the team then measured in their new system.

"While most groups are trying to slow down DNA, our approach is to build faster electronics," says Drndic. "We combined the most sensitive electronics with the most sensitive solid-state nanopores."

"It's very exciting to be able to make purely electronic measurements of single molecules," says Rosenstein. "The setup for nanopore measurements is very simple and portable. It doesn't require a complicated microscope or high powered instruments; it just requires attention to detail. You can easily imagine nanopore technology having a major impact on DNA sequencing and other medical applications within the next few years."

Shepard's group is continuing to improve these techniques. "With a next-generation design," he says, "we may be able to get a further 10X improvement, and measure things that last only 100 nanoseconds. Our lab is also working with other electronic single-molecule techniques based on carbon nanotube transistors, which can leverage similar electronic circuits. This is an exciting time!"

This research has been funded by the National Institutes of Health, the Semiconductor Research Corporation, and the Office of Naval Research.

Columbia Engineering

Columbia University's Fu Foundation School of Engineering and Applied Science, founded in 1864, offers programs in nine departments to both undergraduate and graduate students. With facilities specifically designed and equipped to meet the laboratory and research needs of faculty and students, Columbia Engineering is home to NSF-NIH funded centers in genomic science, molecular nanostructures, materials science, and energy, as well as one of the world's leading programs in financial engineering. These interdisciplinary centers are leading the way in their respective fields while individual groups of engineers and scientists collaborate to solve some of modern society's more difficult challenges. http://www.engineering.columbia.edu/

Holly Evarts | EurekAlert!
Further information:
http://www.columbia.edu

More articles from Life Sciences:

nachricht Lab-free infection test could eliminate guesswork for doctors
26.02.2020 | University of Southampton

nachricht MOF co-catalyst allows selectivity of branched aldehydes of up to 90%
26.02.2020 | National Centre of Competence in Research (NCCR) MARVEL

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: High-pressure scientists in Bayreuth discover promising material for information technology

Researchers at the University of Bayreuth have discovered an unusual material: When cooled down to two degrees Celsius, its crystal structure and electronic properties change abruptly and significantly. In this new state, the distances between iron atoms can be tailored with the help of light beams. This opens up intriguing possibilities for application in the field of information technology. The scientists have presented their discovery in the journal "Angewandte Chemie - International Edition". The new findings are the result of close cooperation with partnering facilities in Augsburg, Dresden, Hamburg, and Moscow.

The material is an unusual form of iron oxide with the formula Fe₅O₆. The researchers produced it at a pressure of 15 gigapascals in a high-pressure laboratory...

Im Focus: From China to the South Pole: Joining forces to solve the neutrino mass puzzle

Study by Mainz physicists indicates that the next generation of neutrino experiments may well find the answer to one of the most pressing issues in neutrino physics

Among the most exciting challenges in modern physics is the identification of the neutrino mass ordering. Physicists from the Cluster of Excellence PRISMA+ at...

Im Focus: Therapies without drugs

Fraunhofer researchers are investigating the potential of microimplants to stimulate nerve cells and treat chronic conditions like asthma, diabetes, or Parkinson’s disease. Find out what makes this form of treatment so appealing and which challenges the researchers still have to master.

A study by the Robert Koch Institute has found that one in four women will suffer from weak bladders at some point in their lives. Treatments of this condition...

Im Focus: A step towards controlling spin-dependent petahertz electronics by material defects

The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.

Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

Melting properties determine the biological functions of the cuticular hydrocarbon layer of ants

26.02.2020 | Interdisciplinary Research

Lights, camera, action... the super-fast world of droplet dynamics

26.02.2020 | Power and Electrical Engineering

Lab-free infection test could eliminate guesswork for doctors

26.02.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>