'Breathalyzers' May Be Useful for Medical Diagnostics

The researchers demonstrated their approach is capable of rapidly detecting biomarkers in the parts per billion to parts per million range, at least 100 times better than previous breath-analysis technologies, said Carlos Martinez, an assistant professor of materials engineering at Purdue who is working with researchers at the National Institute of Standards and Technology.

"People have been working in this area for about 30 years but have not been able to detect low enough concentrations in real time," he said."We solved that problem with the materials we developed, and we are now focusing on how to be very specific, how to distinguish particular biomarkers."

The technology works by detecting changes in electrical resistance or conductance as gases pass over sensors built on top of"microhotplates," tiny heating devices on electronic chips. Detecting biomarkers provides a record of a patient's health profile, indicating the possible presence of cancer and other diseases.

"We are talking about creating an inexpensive, rapid way of collecting diagnostic information about a patient," Martinez said."It might say, 'there is a certain percentage that you are metabolizing a specific compound indicative of this type of cancer,' and then additional, more complex tests could be conducted to confirm the diagnosis."

The researchers used the technology to detect acetone, a biomarker for diabetes, with a sensitivity in the parts per billion range in a gas mimicking a person's breath.

Findings were detailed in a research paper that appeared earlier this year in the IEEE Sensors Journal, published by the Institute of Electrical and Electronics Engineers' IEEE Sensors Council. The paper was co-authored by Martinez and NIST researchers Steve Semancik, lead author Kurt D. Benkstein, Baranidharan Raman and Christopher B. Montgomery.

The researchers used a template made of micron-size polymer particles and coated them with far smaller metal oxide nanoparticles. Using nanoparticle-coated microparticles instead of a flat surface allows researchers to increase the porosity of the sensor films, increasing the"active sensing surface area" to improve sensitivity.

A droplet of the nanoparticle-coated polymer microparticles was deposited on each microhotplate, which are about 100 microns square and contain electrodes shaped like meshing fingers. The droplet dries and then the electrodes are heated up, burning off the polymer and leaving a porous metal-oxide film, creating a sensor.

"It's very porous and very sensitive," Martinez said."We showed that this can work in real time, using a simulated breath into the device."

Gases passing over the device permeate the film and change its electrical properties depending on the particular biomarkers contained in the gas.

Such breathalyzers are likely a decade or longer away from being realized, in part because precise standards have not yet been developed to manufacture devices based on the approach, Martinez said.

"However, the fact that we were able to do this in real time is a big step in the right direction," he said.

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Out-Sniffing Bomb-Sniffing Dogs

A Tel Aviv University scientist leads a research team that has developed a powerful electronic sensor to detect multiple kinds of explosives -- including those used in the recent Yemeni bomb threat. Based on nanotechnology advances, the new sensor is small, portable, and is more sensitive and reliable at detecting explosives than any sniffer dog, says its lead researcher Prof. Fernando Patolsky of Tel Aviv University's Raymond and Beverly Sackler School of Chemistry.

With scientific findings on it published recently in the journalAngewandte Chemie, the new device is attracting considerable attention from security companies and fellow scientists.

Capable of detecting numerous types of explosives, Prof. Patolsky says the sensor is especially effective at detecting TNT. Existing methods and devices used to trace the explosive have the drawbacks of high cost, lengthy decoding times, size, and a need for expert analyses:"There is a need for a small, inexpensive, handheld instrument capable of detecting explosives quickly, reliably and efficiently," says Patolsky.

According to the researchers, this new sensor can out-sniff even a champion sniffer canine.

Portable and hidden from view

The device is made from an array of silicon nanowires, coated with a compound that binds to explosives to form an electronic device -- a nanotransistor. In order to enhance the chips' sensitivity even further, the scientists developed each one with 200 individual sensors that work in harmony to detect different kinds of explosives with an unprecedented degree of reliability, efficiency and speed.

One major advantage of the new sensor is its portability -- it can be carried from place to place by hand. It is also capable of detecting explosives at a distance. It can be mounted on a wall, with no need to bring it into contact with the item being checked. And unlike other explosives sensors, it enables definitive identification of the explosive that it has detected. To date. the device has not had a single detection error.

Security companies are taking note. The American company Nanergy Inc. has developed a prototype based on the patent, and is already in contact with potential partners to develop explosives sensors for the commercial market.

Headed by Prof. Patolsky, who recently returned to Israel from Harvard University, the research team is considered to be one of the world's leaders in developing nano-based sensors that can detect chemical and biological molecules.

Such sensors may be used to detect not only explosives, but also biological toxins and threats, such as anthrax, cholera or botulinum. Looking beyond national security, the sensor offers attractive applications in the medical field as well.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

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Magnetic Trapping Will Help Unlock the Secrets of Anti-Matter

As part of a major international experiment called ALPHA, based at CERN in Switzerland, researchers have helped to achieve trapping and holding atoms of 'anti-hydrogen', which has not previously been possible.

The project involves physicists at Swansea University led by Professor Mike Charlton, Dr Niels Madsen and Dr Dirk Peter van der Werf and the University of Liverpool under Professor Paul Nolan, all supported by the Engineering and Physical Sciences Research Council (EPSRC).

This breakthrough will make it possible to study 'anti-matter' closely for the first time, and so develop unprecedented insight into its composition/structure and improve understanding of the fundamental physical principles that underpin the Universe and the way it works.

For nearly a decade, scientists have been able to undertake the controlled production of anti-hydrogen atoms in the laboratory -- a breakthrough which Swansea University also contributed to, with EPSRC support. But as anti-matter particles are instantly annihilated when they come into contact with matter, it has not, until now, been feasible to study anti-hydrogen atoms in any detail.

ALPHA has therefore developed techniques that not only cool and slow down the anti-particles that make up anti-hydrogen and gently mix them to produce anti-hydrogen atoms, but also trap some of the anti-atoms for long enough so they can be studied.

The key focus of this effort has been the development of electromagnetic traps that have a number of cold species inside. These traps don't just provide the conditions needed to cool the anti-particles prior to mixing. The cold anti-atoms formed also have a tiny 'magnetic moment' which means they respond to magnetic fields. By arranging the magnet coils in the right way, it is possible to set up a magnetic 'well' in the centre of the anti-particle mixing zone where anti-hydrogen has been trapped.

"Every type of particle has its anti-matter equivalent which is its mirror image in terms of having, for instance, the opposite electrical charge" says Professor Charlton."Because hydrogen is the simplest of all atoms, anti-hydrogen is the easiest type of anti-matter to produce in the laboratory. By studying it for the first time, we will be able to understand its properties and establish whether it really is the exact mirror image of hydrogen.

"That understanding will hopefully enable us to shed light on exactly why almost everything in the known Universe consists of matter, rather than anti-matter, and what the implications are in terms of the fundamental way that the Universe functions."

In order to detect the anti-hydrogen atoms they were released from the trap. The silicon detector used to determine the positions of the resulting annihilations was developed and built at Liverpool. Professor Nolan comments that"the unique clean room and workshop facilities in Liverpool, together with detector and electronics expertise, allowed us to build this complex and unique instrument that is now part of the ALPHA experiment."

Dr Niels Madsen notes:"Trapping of anti-hydrogen is a major breakthrough in antimatter physics. Having the anti-atoms trapped will allow for comparisons of matter and anti-matter to a level that until now would have been considered wishful thinking."

The initiative is expected to run for several years, with ALPHA commencing tests on anti-hydrogen atoms in around five years time.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

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Intelligent Detector Provides Real-Time Information on Available Parking Spaces

Testing of the new technology is currently underway at the Universitat Politècnica de Catalunya's North Campus, and a patent is being sought. The system can be used to provide users with information via mobile devices such as phones, laptop computers, and iPads, or using luminous panels in public thoroughfares. In the coming months it will be installed in the 22@Barcelona innovation district and in downtown Figueres.

A team at the Department of Electronic Engineering of the Castelldefels School of Telecommunications and Aerospace Engineering (EETAC), part of the Universitat Politècnica de Catalunya (UPC), has designed a new method for continuously detecting the presence of vehicles using both an optical and a magnetic sensor. The detector incorporates the two sensors in a 4 by 13 cm casing that is set into the pavement of each parking space. Urbiòtica, a company set up by UPC professors and their industrial partners, is testing the system at the UPC's North Campus prior to placing it on the market.

The device works by first detecting the sudden change in the amount of light reaching the pavement that occurs when a vehicle passes over it. The optical sensor then activates the magnetic sensor to verify that the shadow is being produced by a vehicle. This is done by detecting the slight disturbance in Earth's magnetic field that occurs when a car passes over or stops above the device. The two sensors are connected to a microcontroller that executes an algorithm to determine whether or not a vehicle is present. The system's optical sensor is always active but consumes an insignificant amount of power.

When a vehicle is detected, the microcontroller sends a radio-frequency signal, which conveys this information to an antenna connected to a transceiver. This way of transmitting signals is much more economical than using wiring. The transceiver, designed for installation on street lights, receives the information and transmits it to the database or control center within seconds (using technologies such as Wi-Fi or GPRS). Potential clients for the system include municipal services and parking lot operators.

According to Ramon Pallàs, head of the UPC team that developed the technology (for which a patent is being sought), the plan is to make the information available on luminous panels on public thoroughfares. Users will also be able to receive parking information on mobile devices such as phones, laptop computers, and iPads.

The innovative features of the product (which the UPC's AntenaLAB group also worked on) relate to the field of sensors, the circuits connecting the sensors to the microcontroller, the method for supplying power to the sensors, and management of the power supply for the system as a whole.

Continuous operation with low power consumption

The invention overcomes the shortcomings of the best existing systems for detecting stationary vehicles. There currently exist devices that emit a signal when a car passes over a sensor, but they do not detect whether the vehicle stops. In an enclosed facility these systems can be used to count vehicles entering and leaving and thus determine the number of parking spaces available, but they do not indicate where the free spaces are. Also, the magnetic sensors now in use consume too much energy to be kept running all the time.

In contrast, the system developed by the UPC group and marketed by Urbiòtica operates continuously and uses very little power because the optical sensor is the only component that is always active and the magnetic sensor is activated less frequently than in other similar systems. The fact that the sensors are connected directly to the microcontroller, without any intermediate electronic circuit, also reduces power consumption.

Practical applications

The new system can be used to manage and monitor vehicles on public and private thoroughfares, particularly in urban areas. This makes it possible to monitor points of access to centers of population, restricted zones, security zones, and grade crossings, and to manage parking on streets, at airports, and in commercial and underground parking areas. These applications can reduce the time drivers spend looking for a parking spot, resulting in lower fuel consumption and less pollution.

The characteristics of the system also facilitate other applications, such as the reservation of parking spaces for disabled drivers and payment based on the real time that a parking space is used. The system could also be used to detect areas where lighting is absent or insufficient.

Once pilot testing has been successfully completed, the system will be installed in the 22@Barcelona innovation district (from December on) as part of a Barcelona City Council project to deploy sensor systems, and in the town of Figueres (early in 2011), where it will be used to monitor traffic entering and leaving the city center.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

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