Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Chemical Sensor on a Chip

Published: Friday, June 13, 2014
Last Updated: Monday, July 07, 2014
Bookmark and Share
Using miniaturized laser technology, a tiny sensor has been built at the Vienna University of Technology which can test the chemical composition of liquids.

They are invisible, but perfectly suited for analysing liquids and gases; infrared laser beams are absorbed differently by different molecules. This effect can for instance be used to measure the oxygen concentration in blood. At the Vienna University of Technology, this technique has now been miniaturized and implemented in the prototype for a new kind of sensor.

Specially designed quantum cascade lasers and light detectors are created by the same production process. The gap between laser and detector is only 50 micrometres. It is bridged by a plasmonic waveguide made of gold and silicon nitride. This new approach allows for the simple and cheap production of tiny sensors for many different applications.

Laser and Detector
Simple solid-state lasers, such as the well-known red ruby laser, consist of only one material. Quantum cascade lasers, on the other hand, are made of a perfectly optimized layer system of different materials. That way, the properties such as the wavelength of the laser can be tuned. When a voltage is applied to the layer structure, the laser starts to emit light. But the structure can also work the other way around; when it is irradiated with light, an electric signal is created.

Now a method has been developed to create a laser and a detector at the same time, on one single chip, in such a way that the wavelength of the laser perfectly matches the wavelength to which the detector is sensitive. This bifunctional material was created atomic layer for atomic layer at the center for micro- and nanostructures at the Vienna University of Technology. “As both parts are created in one step, laser and detector do not have to be adjusted. They are already perfectly aligned”, says Benedikt Schwarz.

Leading the Light to the Detector
In conventional systems, the laser light has to be transmitted to the detector using carefully placed lenses. Alternatively, optical fibres can be used, but they usually transport all the light inside, without letting it interact with the environment, and therefore they cannot be used as sensors. 

In the new element created at the Vienna University of Technology, the optical connection between quantum cascade laser and detector works in a completely different way. It is a plasmonic waveguide, made of gold and silicon nitride. “The light interacts with the electrons in the metal in a very special way, so that the light is guided outside the gold surface”, says Benedikt Schwarz. “That is why the light can be absorbed by the molecules on its way between laser and detector.”

The sensor chip can be submerged in a liquid. By measuring the decrease of the detected light intensity due to the presence of light absorbing molecules, the composition of the liquid can be determined. The sensor was tested with a mixture of water and alcohol. The water concentration can be measured with an accuracy of 0.06%.

As the wavelength can be influenced by changing the design of the layered structure, this sensor concept can be applied to a wide variety of molecules such as carbohydrates or proteins, for many different applications in chemical, biological or medical analytics.


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,500+ scientific posters on ePosters
  • More Than 5,000+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.


Scientific News
Point of Care Diagnostics - A Cautious Revolution
Advances in molecular biology, coupled with the miniaturization and improved sensitivity of assays and devices in general, have enabled a new wave of point-of-care (POC) or “bedside” diagnostics.
Mass Spec Technology Drives Innovation Across the Biopharma Workflow
With greater resolving power, analytical speed, and accuracy, new mass spectrometry technology and techniques are infiltrating the biopharmaceuticals workflow.
One Step Closer to Precision Medicine for Chronic Lung Disease Sufferers
A study led by University of North Carolina at Chapel Hill, and National Jewish Health, has provided evidence of links between SNPs and known COPD blood protein biomarkers.
Researchers Find a Gap in the Brain’s Firewall Against Parkinson’s Disease
Researchers at NIH have found mouse study that identified a key player in the progression of the disorder.
Fat Cells That Amplify Nerve Signals in Response to Cold Also Affect Blood Sugar Metabolism
Researchers at UTSW have found that the protein connexin 43 forms cell-to-cell communication channels on the surface of emerging beige fat cells that amplify the signals from those few nerve fibers.
Scientists Find Lethal Vulnerability in Treatment-Resistant Lung Cancer
The study describes how the drug Selinexor killed lung cancer cells and shrank tumors in mice when used against cancers driven by the aggressive and difficult-to-treat KRAS cancer gene.
Drug to Treat Alcohol Use Disorder Shows Promise Among Drinkers With High Stress
The findings suggest that potential future studies with drugs targeting vasopressin blockade should focus on populations of people with AUD who also report high levels of stress.
C Dots Show Powerful Tumor Killing Effect
Nanoparticles known as Cornell dots, or C dots, have shown great promise as a therapeutic tool in the detection and treatment of cancer.
Charles River Acquires Agilux
Enhances Charles River’s early-stage capabilities in bioanalytical services.
Faecal Bacteria Linked to Body Fat
Researchers at King’s College London have found a new link between the diversity of bacteria in human poo – known as the human faecal microbiome - and levels of abdominal body fat.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
5,000+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!