Navigation Links
Sniffing out a better chemical sensor

Marrying a sensitive detector technology capable of distinguishing hundreds of different chemical compounds with a pattern-recognition module that mimics the way animals recognize odors, researchers at the National Institute of Standards and Technology (NIST) have created a new approach for electronic noses. Described in a recent paper,* their electronic nose is more adept than conventional methodologies at recognizing molecular features even for chemicals it has not been trained to detect and is also robust enough to deal with changes in sensor response that come with wear and tear. The detector could be a potent tool for applications such as sniffing out nerve agents, environmental contaminants, and trace indicators of disease, in addition to monitoring industrial processes and aiding in space exploration.

In animals, odorant molecules in the air enter the nostrils and bind with sensory neurons in the nose that convert the chemical interactions into an electrical signal that the brain interprets as a smell. In humans, there are about 350 types of sensory neurons and many copies of each type; dogs and mice have several hundreds more types of sensory neurons than that. Odor recognition proceeds in a step-by-step fashion where the chemical identity is gradually resolved: initial coarse information (e.g. ice-cream is fruit-flavored vs. chocolate) is refined over time to allow finer discrimination (strawberry vs. raspberry). This biological approach inspired the researchers to develop a parallel divide and conquer method for use with the electronic nose.

The technology is based on interactions between chemical species and semiconducting sensing materials placed on top of MEMS microheater platforms developed at NIST. (See NIST Microhotplate May Help Search for Extraterrestrial Life, NIST Tech Beat, Oct., 2001.) The electronic nose employed in the current work is comprised of eight types of sensors in the form of oxide films deposited on the surfaces of 16 microheaters, with two copies of each material. Precise control of the individual heating elements allows the scientists to treat each of them as a collection of virtual sensors at 350 temperature increments between 150 to 500 C, increasing the number of sensors to about 5,600. The combination of the sensing films and the ability to vary the temperature gives the device the analytical equivalent of a snoot full of sensory neurons.

Much like people detect and remember many different smells and use that knowledge to generalize about smells they havent encountered before, the electronic nose also needs to be trained to recognize the chemical signatures of different smells before it can deal with unknowns. The great advantage of this system, according to NIST researchers Barani Raman and Steve Semancik, is that you dont need to expose the array to every chemical it could come in contact with in order to recognize and/or classify them. Breaking the identification process down into simple, small, discrete steps using the most information rich data also avoids noisy portions of the sensor response, thereby incorporating robustness against the effects of sensor drift or aging.

The researchers say that they are continuing to work on applications involving rapid identification of chemicals in unknown backgrounds or in a complex cocktail.


Contact: Mark Esser
National Institute of Standards and Technology (NIST)

Related biology news :

1. Scat sniffing dogs detecting rare California carnivores
2. New caledonian crows find 2 tools better than 1
3. Restoring sight, advances in fertility treatments and better visibility for pilots at FIO
4. New CPR promises better results by compressing abdomen, not Chest
5. City birds better than rural species in coping with human disruption
6. Doctors learn to control their own brains pain responses to better treat patients
7. Study reveals that immigrant teenagers eat better than Spanish teenagers
8. New membrane strips carbon dioxide from natural gas faster and better
9. New approach builds better proteins inside a computer
10. People who skip meals: are they better off?
11. Researchers successfully simulate photosynthesis and design a better leaf
Post Your Comments:
Related Image:
Sniffing out a better chemical sensor
(Date:10/29/2015)... Oct. 29, 2015  Rubicon Genomics, Inc., today ... distribution of its DNA library preparation products, including ... new ThruPLEX Plasma-seq kit. ThruPLEX Plasma-seq has been ... of NGS libraries for liquid biopsies--the analysis of ... prognostic applications in cancer and other conditions. Eurofins ...
(Date:10/27/2015)... YORK , Oct. 27, 2015 In ... major issues of concern for various industry verticals such ... is due to the growing demand for secure & ... in various ,sectors, such as hacking of bank accounts, ... for electronic equipment such as PC,s, laptops, and smartphones ...
(Date:10/26/2015)... and LAS VEGAS , Oct. 26, ... , an innovator in modern authentication and a founding ... the launch of its latest version of the Nok ... organizations to use standards-based authentication that supports existing and ... Authentication Suite is ideal for organizations deploying customer-facing applications ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... Israel , Nov. 24, 2015  Tikcro Technologies Ltd. (OTCQB: TIKRF) ... on December 29, 2015 at 11:00 a.m. Israel ... Electra Tower, 98 Yigal Allon Street, 36 th Floor, ... of Eric Paneth and Izhak Tamir to the ... Rami Skaliter as external directors; , approval of an amendment to ...
(Date:11/24/2015)...  Twist Bioscience, a company focused on synthetic ... Bioscience chief executive officer, will present at the ... 2015 at 3:10 p.m. Eastern Time at The Lotte New ... --> --> About Twist ... on Twitter. Sign up to follow our Twitter ...
(Date:11/24/2015)... ... 24, 2015 , ... InSphero AG, the leading supplier of easy-to-use solutions for ... Aregger to serve as Chief Operating Officer. , Having joined InSphero in ... and was promoted to Head of InSphero Diagnostics in 2014. There she ...
(Date:11/24/2015)... - ProMetic Life Sciences Inc. (TSX: PLI) (OTCQX: PFSCF) ("ProMetic" ... , President and Chief Executive Officer of ProMetic, will be ... th Annual Healthcare Conference to be held at the ... st , at 8.50am (ET) and ProMetic,s management team ... presentation will be available live via a webcast accessible at ...
Breaking Biology Technology: