New Device May Put DNA Testing in Doctors' Hands

A U.K.-based company, QuantuMDX, has built a working prototype of a device, shown here, that they hope will allow doctors to perform genetic tests within 15 minutes. The "x-ray" section of this image shows the nanowire biosensor chip and electronics.
Credit: QuantuMDx Group Ltd


It can take days for doctors to determine if a patient infected with malaria carries a drug-resistant version of the disease. The same is true of tuberculosis.

But a new testing device could reduce that time lag to 15 minutes, potentially helping to ensure that patients are correctly treated right away, says the company developing this device.

United Kingdom company QuantuMDX now has a working prototype for a device intended to quickly test a sample of blood, sputum (saliva mixed with mucus) or even tumor cells for genetic markers that provide information to guide a doctor's decisions on how to treat a patient. [7 Diseases You Can Learn About from a Genetic Test]


"We want to put a full diagnostic test into the palms of health professionals' hands," said Elaine Warburton, chief executive officer of QuantuMDX and the company’s cofounder.

The prototype is about the size of an iPad 5, or 6.6 by 9.4 inches (17 by 24 centimeters), but thicker. In about six months, Warburton said she anticipates the device will be reduced to about the size of an iPad mini, 5.3 by 7.9 in. (13 by 200 cm).

To use it, a doctor would put a sample from a patient into a credit-card sized, disposable cartridge and pop the cartridge into the device for analysis, she said. So far, the prototype has shown success in producing DNA test results from blood. ..

The sensor in the device is intended to detect, for example, if a person is infected by the malaria parasite, which species of parasite is responsible for the infection and whether the parasite is resistant to antimalarial medications.

Detection happens when fragments of parasite DNA from the sample bind to complementary strands, or probes, in the cartridge. These probes are associated with nanowires, thin pieces of silicon etched into a computer chip. The binding produces an electrical change in the wires, which the device interprets as a positive result.

This basic technique can be applied in many ways. QuantuMDX is developing applications that could one day provide information about tumor cells, or determine if someone has genetic variations that will affect his or her response to the blood-thinning drug warfarin. And the company has received proposals from people interested in using it in everything from veterinary work to forensics, Warburton said.

The device, currently known as Q-POC (pronounced Q-pock), is still a long way from being used in the clinic. The company still has work to do on the cartridges for use with the handheld prototype, and it needs to run clinical trials testing the device, followed by regulatory approval from bodies such as FDA, Warburton told LiveScience in an email.

Earlier this month at the Consumer Electronics Show in Las Vegas, Jonathan O'Halloran, inventor of the technology and the company's cofounder, announced plans to launch a crowdfunding campaign. The campaign is expected to begin on Feb. 12 on the site Indigogo.com, to support further development of the Q-POC. The company is also interested in suggestions for a new name and design for the device, Warburton said.

If all goes well, QuantuMDX anticipates commercially launching the device and malaria test cartridge in Africa in 2015, she said.

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ORIGINAL: Live Science

By Wynne Parry, LiveScience Contributor

January 16, 2014

Making Wires For Drug-Releasing Circuits

ORIGINAL: ACS - Chemical and Engineering News
By Katherine Bourzac
July 31, 2013

Bioengineering: Nanowires loaded with biochemicals can release their cargo in response to an electrical signal
Department: Science & Technology | Collection: Life Sciences
News Channels: Nano SCENE, Materials SCENE, Biological SCENE
Keywords: nanowires, controlled drug release

Glowing Nanowires A flexible nanostorage device (left) consists of a polyimide film coated with gold and chemical-storing nanowires. When a voltage is applied to the film, the nanowires release adenosine triphosphate (right). The area around the wires glows because the released ATP triggers enzymes to produce a bioluminescent molecule. If the researchers turn off the voltage, the wires no longer glow (center). Credit: ACS Nano

Bioengineers have designed chips that release precise doses of drugs when activated by electrical signals. Although these devices promise drug delivery to diseased tissue on cue, they are rigid, which isn’t ideal for an implant. There are more flexible materials that deliver bioactive compounds, but they do so constantly as the material slowly dissolves. Now, researchers at Seoul National University have combined flexibility and controlled release in multifunctional nanowires that discharge stored chemicals in response to an electrical signal (ACS Nano 2013, DOI: 10.1021/nn402082v).

Seunghun Hong, a nanotechnologist at Seoul National University, thinks his team’s nanowires could one day be integrated into implants like hip replacements to release an antibiotic to cure an infection. Or they could be integrated into diagnostic chips to release chemicals without need for pumps.

The researchers made the nanowires to act as electrically controlled chemical storage units. The nanowires have three segments: an electrically active polymer mixed with the chemical to be stored; a nickel segment that allows the researchers to move the wires with a magnet; and a gold or silver section that acts as an electrical contact, so that the wires can be integrated on a chip. When a voltage is applied to the polymer, it expands, releasing the chemicals trapped inside its matrix.

To make the nanowires, Hong and his group used an existing method that relies on an anodized aluminum oxide template. The template has holes 200 nm in diameter and 60 µm deep. The researchers sequentially electroplate the template with the three different materials, first filling the holes with some gold, then some nickel, then some polypyrrole mixed with the chemical of choice. Once filled, the scientists dissolve away the template, freeing the nanowires.

In one test of the wires, Hong’s group chose to store and release adenosine triphosphate (ATP), a chemical that stores energy in biological systems. They dispersed the nanowires into a solution and used magnetic fields to pull the nanowires down to precise locations on a conductive nickel surface. The solution also contained a collection of enzymes that could turn the compound luciferin into a fluorescent molecule in the presence of ATP. When the researchers applied voltage to the nanowires, the area around the wires lit up, indicating the release of ATP.

In another experiment, the researchers placed the nanowires on a conductive gold surface along with the biological motor protein kinesin, which runs on ATP. When they applied a voltage to the surface, the motors moved in response to the released ATP.

Reginald M. Penner, a chemist at the University of California, Irvine, says other groups have made tiny storage tubes out of electrically conductive polymers before, but Hong’s is the first to demonstrate that they can be integrated with electronics to control them. This electronic integration and control, he says, “is absolutely enabling for an implantable drug delivery system.”

Chemical & Engineering NewsISSN 0009-2347Copyright © 2013 American Chemical Society

Nanowire solar cells raises efficiency limit

ORIGINAL: Niels Bohr Institut

Scientists from the Nano-Science Center at the Niels Bohr Institut, Denmark and the Ecole Polytechnique Fédérale de Lausanne, Switzerland, have shown that a single nanowire can concentrate the sunlight up to 15 times of the normal sun light intensity. The results are surprising and the potential for developing a new type of highly efficient solar cells is great.

Nanowire crystals used as the solar cells. SEM (Scaning Electron Microscope) image of GaAs nanowire crystal grown on a Silicon substrate

- Due to some unique physical light absorption properties of nanowires, the limit of how much energy we can utilize from the sun's rays is higher than previous believed. These results demonstrate the great potential of development of nanowire-based solar cells, says PhD Peter Krogstrup on the surprising discovery that is described in the journal Nature Photonics.

The research groups have during recent years studied how to develop and improve the quality of the nanowire crystals, which is a cylindrical structure with a diameter of about 10,000 part of a human hair. The nanowires are predicted to have great potential in the development not only of solar cells, but also of future quantum computers and other electronic products.

- It turns out that the nanowires naturally concentrate the sun's rays into a very small area in the crystal by up to a factor 15. Because the diameter of a nanowire crystal is smaller than the wavelength of the light coming from the sun it can cause resonances in the intensity of light in and around nanowires. Thus, the resonances can give a concentrated sunlight, where the energy is converted, which can be used to give a higher conversion effeciency of the sun's energy, says Peter Krogstrup, who with this discovery contributes to that the research in solar cell technology based on nanowires get a real boost.

The figure shows that the sun's rays are drawn into a nanowire, which stands on a substrate. At a given wavelength the sunlight is concentrated up to 15 times. Consequently, there is great potential in using nanowires in the development of future solar cells. (credit: Niels Bohr Institute)

New efficiency limit

The typical efficiency limit - the so-called "Shockley-Queisser Limit" - is a limit, which for many years has been a landmark for solar cells efficiency among researchers, but now it seems that it may be increased.

- It's exciting as a researcher to move the theoretical limits, as we know. Although it does not sound like much, that the limit is moved by only a few percent, it will have a major impact on the development of solar cells, exploitation of nanowire solar rays and perhaps the extraction of energy at international level. However, it will take some years years before production of solar cells consisting of nanowires becomes a reality, says Peter Krogstrup who just completed his PhD at the Niels Bohr Institute, University of Copenhagen.

The research is conducted in collaboration with the Laboratory des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, the Foundation and the company SunFlake A / S. Their scientific findings work support results published in the journal Science in January. Here, a group of researchers from Lund, showed that the sun’s rays was sucked into the nanowires due to the high amount of power that their solar cell produced.

Article in Nature Photonics >>

Article in Science, January 2013 >>