Navigation Links
Nanowire-based sensors offer improved detection of volatile organic compounds

A team of researchers from the National Institute of Standards and Technology (NIST), George Mason University and the University of Maryland has made nano-sized sensors that detect volatile organic compoundsharmful pollutants released from paints, cleaners, pesticides and other productsthat offer several advantages over today's commercial gas sensors, including low-power room-temperature operation and the ability to detect one or several compounds over a wide range of concentrations.

The recently published work* is proof of concept for a gas sensor made of a single nanowire and metal oxide nanoclusters chosen to react to a specific organic compound. This work is the most recent of several efforts at NIST that take advantage of the unique properties of nanowires and metal oxide elements for sensing dangerous substances.

Modern commercial gas sensors are made of thin, conductive films of metal oxides. When a volatile organic compound like benzene interacts with titanium dioxide, for example, a reaction alters the current running through the film, triggering an alarm. While thin-film sensors are effective, many must operate at temperatures of 200 C (392 F) or higher. Frequent heating can degrade the materials that make up the films and contacts, causing reliability problems. In addition, most thin-film sensors work within a narrow range: one might catch a small amount of toluene in the air, but fail to sniff out a massive release of the gas. The range of the new nanowire sensors runs from just 50 parts per billion up to 1 part per 100, or 1 percent of the air in a room.

These new sensors, built using the same fabrication processes that are commonly used for silicon computer chips, operate using the same basic principle, but on a much smaller scale: the gallium nitride wires are less than 500 nanometers across and less than 10 micrometers in length. Despite their microscopic size, the nanowires and titanium dioxide nanoclusters they're coated with have a high surface-to-volume ratio that makes them exquisitely sensitive.

"The electrical current flowing through our nanosensors is in the microamps range, while traditional sensors require milliamps," explains NIST's Abhishek Motayed. "So we're sensing with a lot less power and energy. The nanosensors also offer greater reliability and smaller size. They're so small that you can put them anywhere." Ultraviolet light, rather than heat, promotes the titanium dioxide to react in the presence of a volatile organic compound.

Further, each nanowire is a defect-free single crystal, rather than the conglomeration of crystal grains in thin-film sensors, so they're less prone to degradation. In reliability tests over the last year, the nano-sized sensors have not experienced failures. While the team's current experimental sensors are tuned to detect benzene as well as the similar volatile organic compounds toluene, ethylbenzene and xylene, their goal is to build a device that includes an array of nanowires and various metal oxide nanoclusters for analyzing mixtures of compounds. They plan to collaborate with other NIST teams to combine their ultraviolet light approach with heat-induced nanowire sensing technologies.


Contact: Michael Baum
National Institute of Standards and Technology (NIST)

Related biology technology :

1. Biochips: Genosensors, Microarrays, Labs-On-The-Chip
2. New graphene discovery boosts oil exploration efforts, could enable self-powered microsensors
3. Finesse Launches the VirtualTransmitter Module and TruFluor Transmitter Blades for Seamless Integration of Single-Use Sensors Into Bioreactor Control
4. Finesse Solutions Introduces New T700 cGMP Upstream Processing Platform Featuring G3 Hardware and Fully Integrated Single-Use Sensors
5. Finesse Solutions Showcases SmartBag with Fully Integrated Single-Use pH and pO2 Sensors for Rocker Bioreactors at Interphex 2011
6. UV-transparent coating for image sensors
7. Sensors to detect explosives, monitor food being developed at UH
8. Lower-Cost ZIF and LIF-Compatible Connection Option for Tekscan Custom Force Sensors
9. ActiveCare, Inc. Announces Strategic Relationship With Vista Therapeutics, Inc. in Developing Nano Biosensors for the Elderly
10. Tiny sensors tucked into cell phones could map airborne toxins in real time
11. Hothead Technologies Partners with Sivix Logistics to Add Customized Handheld Monitors and Autonomous Sensors to its Product Line
Post Your Comments:
Related Image:
Nanowire-based sensors offer improved detection of volatile organic compounds
(Date:6/27/2016)... , June 27, 2016 /PRNewswire/ - BIOREM Inc. (TSX-V: ... been advised by its major shareholders, Clean Technology Fund ... United States based venture capital funds ... of Biorem (on a fully diluted, as converted basis), ... disposition of their entire equity holdings in Biorem to ...
(Date:6/27/2016)... Raleigh, NC (PRWEB) , ... June 27, 2016 ... ... a mission to bring innovative medical technologies, services and solutions to the healthcare ... development and implementation of various distribution, manufacturing, sales and marketing strategies that are ...
(Date:6/24/2016)... discussions on a range of subjects including policies, debt and ... Poloz. Speaking at a lecture to the Canadian ... to the country,s inflation target, which is set by both ... "In certain areas there needs to be ... why not sit down and address strategy together?" ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... release of its second eBook, “Clinical Trials Patient Recruitment and Retention Tips.” Partnering ... retention in this eBook by providing practical tips, tools, and strategies for clinical ...
Breaking Biology Technology:
(Date:6/20/2016)... 20, 2016 Securus Technologies, a leading ... for public safety, investigation, corrections and monitoring announced ... it has secured the final acceptance by all ... Managed Access Systems (MAS) installed. Furthermore, Securus will ... be installed by October, 2016. MAS distinguishes between ...
(Date:6/9/2016)... , June 9, 2016 ... Police deploy Teleste,s video security solution to ensure the safety ... France during the major tournament Teleste, ... communications systems and services, announced today that its video security ... to back up public safety across the country. ...
(Date:6/2/2016)... , June 2, 2016   The Weather Company , ... Watson Ads, an industry-first capability in which consumers will be ... able to ask questions via voice or text and receive ... Marketers have long sought an advertising ... that can be personal, relevant and valuable; and can scale ...
Breaking Biology News(10 mins):