Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Hydrogels used to make precise new sensor

This diagram depicts a new type of "diffraction-based" sensor made of thin stripes of a gelatinous material called a hydrogel, which expands and contracts depending on the acidity of its environment. The new type of biological and chemical sensor has few moving parts and works by precisely determining pH, revealing the identity of substances in liquid environments such as water or blood. The microscopic images at bottom show how the hydrogel stripes expand with decreasing acidity. (Birck Nanotechnology Center, Purdue University)
This diagram depicts a new type of "diffraction-based" sensor made of thin stripes of a gelatinous material called a hydrogel, which expands and contracts depending on the acidity of its environment. The new type of biological and chemical sensor has few moving parts and works by precisely determining pH, revealing the identity of substances in liquid environments such as water or blood. The microscopic images at bottom show how the hydrogel stripes expand with decreasing acidity. (Birck Nanotechnology Center, Purdue University)

Abstract:
Researchers are developing a new type of biological and chemical sensor that has few moving parts, is low-cost and yet highly sensitive, sturdy and long-lasting.

Hydrogels used to make precise new sensor

West Lafayette, IN | Posted on February 8th, 2011

The "diffraction-based" sensors are made of thin stripes of a gelatinous material called a hydrogel, which expands and contracts depending on the acidity of its environment.

Recent research findings have demonstrated that the sensor can be used to precisely determine pH - a measure of how acidic or basic a liquid is - revealing information about substances in liquid environments, said Cagri Savran (pronounced Chary Savran), an associate professor of mechanical engineering at Purdue University.

The sensor's simple design could make it more practical than other sensors in development, he said.

"Many sensors being developed today are brilliantly designed but are too expensive to produce, require highly skilled operators and are not robust enough to be practical," said Savran, whose work is based at Purdue's Birck Nanotechnology Center in the university's Discovery Park.

New findings show the technology is highly sensitive and might be used in chemical and biological applications including environmental monitoring in waterways and glucose monitoring in blood.

"As with any novel platform, more development is needed, but the detection principle behind this technology is so simple that it wouldn't be difficult to commercialize," said Savran, who is collaborating with another team of researchers led by Babak Ziaie, a Purdue professor of electrical and computer engineering and biomedical engineering.

Findings are detailed in a paper presented during the IEEE Sensors 2010 Conference in November and also published in the conference proceedings. The paper was written by postdoctoral researcher Chun-Li Chang, doctoral student Zhenwen Ding, Ziaie and Savran.

The flexible, water-insoluble hydrogel is formed into a series of raised stripes called a "diffraction grating," which is coated with gold on both the stripe surfaces and the spaces in between. The stripes expand and contract depending on the pH level of the environment.

Researchers in Ziaie's lab fabricated the hydrogel, while Savran's group led work in the design, development and testing of the diffraction-based sensor.

The sensors work by analyzing laser light reflecting off the gold coatings. Reflections from the stripes and spaces in between interfere with each other, creating a "diffraction pattern" that differs depending on the height of the stripes.

These diffraction patterns indicate minute changes in the movement of the hydrogel stripes in response to the environment, in effect measuring changes in pH.

"By precise measurement of pH, the diffraction patterns can reveal a lot of information about the sample environment," said Savran, who by courtesy is an associate professor of biomedical engineering and electrical and computer engineering. "This technology detects very small changes in the swelling of the diffraction grating, which makes them very sensitive."

The pH of a liquid is recorded on a scale from 0 to 14, with 0 being the most acidic and 14 the most basic. Findings showed the device's high sensitivity enables it to resolve changes smaller than one-1,000th on the pH scale, measuring swelling of only a few nanometers. A nanometer is about 50,000 times smaller than the finest sand grain.

"We know we can make them even more sensitive," Savran said. "By using different hydrogels, gratings responsive to stimuli other than pH can also be fabricated."

The work is ongoing.

"It's a good example of collaborations that can blossom when labs focusing on different research are located next to each other," Savran said. "Professor Ziaie's lab was already working with hydrogels, and my group was working on diffraction-based sensors. Hearing about the hydrogels work next door, one of my postdoctoral researchers, Chun-Li Chang thought of making a reflective diffraction grating out of hydrogels."

The Office of Technology Commercialization of the Purdue Research Foundation has filed for U.S. patent protection on the concept.

ABSTRACT

Diffractometric Biochemical Sensing with Smart Hydrogels


Chun-Li Changab, Zhenwen Dingbc, Venkata N. L. R. Patchigollaab, Babak Ziaiebd, and Cagri A. Savranab

aSchool of Mechanical Engineering, bBirck Nanotechnology Center, cDepartment of Physics, dSchool of Electrical and Computer Engineering, Purdue University


We report reflective diffraction gratings made from smart hydrogels for ultrasensitive biochemical detection. As an example for a biochemically responsive hydrogel, we chose a pH-sensitive hydrogel to construct diffraction gratings that swell or shrink due to changes in pH. Interferometric analysis of the grating enabled detection of the hydrogel's swelling/shrinking with nanoscale precision with a resolution of 610-4 pH units. The developed system is remarkably simple both to fabricate and operate. Moreover, the concept of the hydrogel grating is generic and can be widely applied to hydrogels responsive to other stimuli.

####

For more information, please click here

Contacts:
Writer:
Emil Venere
765-494-4709


Sources:
Cagri A. Savran
765 494-8601


Babak Ziaie
765-494-0725


Copyright © Purdue University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Researchers find the 'key' to quantum network solution May 25th, 2015

One step closer to a single-molecule device: Columbia Engineering researchers first to create a single-molecule diode -- the ultimate in miniaturization for electronic devices -- with potential for real-world applications May 25th, 2015

DNA Double Helix Does Double Duty in Assembling Arrays of Nanoparticles: Synthetic pieces of biological molecule form framework and glue for making nanoparticle clusters and arrays May 25th, 2015

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

Possible Futures

Simulations predict flat liquid May 21st, 2015

Nature inspires first artificial molecular pump: Simple design mimics pumping mechanism of life-sustaining proteins found in living cells May 19th, 2015

NNCO and Museum of Science Fiction to Collaborate on Nanotechnology and 3D Printing Panels at Awesome Con May 19th, 2015

Quantum 'gruyres' for spintronics of the future: Topological insulators become a little less 'elusive' May 12th, 2015

Academic/Education

SUNY Poly CNSE and NIOSH Launch Federal Nano Health and Safety Consortium: May 20th, 2015

New JEOL E-Beam Lithography System to Enhance Quantum NanoFab Capabilities May 6th, 2015

FEI Partners With the George Washington University to Equip New Science & Engineering Hall: Suite of new high-performance microscopes will be used for cutting-edge experiments at GWs new research facility April 29th, 2015

Renishaw Raman systems used to study 2D materials at Boston University, Massachusetts, USA. April 28th, 2015

Sensors

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Record high sensitive Graphene Hall sensors May 21st, 2015

Graphene enables tunable microwave antenna May 15th, 2015

Janusz Bryzek Joins MEMS Industry Group to Lead New TSensors Division - New Division will Focus on Accelerating Development of Emerging Ultra-high Volume Sensors Supporting Abundance, mHealth and IoT May 14th, 2015

Announcements

Researchers find the 'key' to quantum network solution May 25th, 2015

One step closer to a single-molecule device: Columbia Engineering researchers first to create a single-molecule diode -- the ultimate in miniaturization for electronic devices -- with potential for real-world applications May 25th, 2015

DNA Double Helix Does Double Duty in Assembling Arrays of Nanoparticles: Synthetic pieces of biological molecule form framework and glue for making nanoparticle clusters and arrays May 25th, 2015

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

Environment

Conversion of Greenhouse Gases to Syngas in Presence of Nanocatalysts in Iran May 22nd, 2015

Directa Plus in Barcelona to present the innovative project GEnIuS for oil spills clean-up activities: The company has created a graphene-based product for the remediation of water contaminated by oil and hydrocarbons May 21st, 2015

Nano-policing pollution May 13th, 2015

Chemists strike nano-gold: 4 new atomic structures for gold nanoparticle clusters: Research builds upon work by Nobel Prize-winning team from Stanford University April 28th, 2015

Water

Nanosorbent Produced in Iran to Adsorb Tiny Amounts of Aromatic Hydrocarbon from Seawater May 18th, 2015

Iran Unveils New Home-Made Medicines, Nanotechnology Products May 14th, 2015

Plugging up leaky graphene: New technique may enable faster, more durable water filters May 7th, 2015

Production of Industrial Nano-Membrane for Water, Wastewater Purification Device in Iran May 2nd, 2015

Nanobiotechnology

DNA Double Helix Does Double Duty in Assembling Arrays of Nanoparticles: Synthetic pieces of biological molecule form framework and glue for making nanoparticle clusters and arrays May 25th, 2015

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Supercomputer unlocks secrets of plant cells to pave the way for more resilient crops: IBM partners with University of Melbourne and UQ May 21st, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project