Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > New lab-on-chip advance uses low-cost, disposable paper strips

Colored water is used to show how liquid wicks along tiny channels formed in paper using a laser, in research to develop a new technology for medical diagnostics and chemical analysis. Silica microparticles were deposited on patterned areas, allowing liquid to diffuse from one end of a channel to the other. (Birck Nanotechnology Center, Purdue University)
Colored water is used to show how liquid wicks along tiny channels formed in paper using a laser, in research to develop a new technology for medical diagnostics and chemical analysis. Silica microparticles were deposited on patterned areas, allowing liquid to diffuse from one end of a channel to the other. (Birck Nanotechnology Center, Purdue University)

Abstract:
Researchers have invented a technique that uses inexpensive paper to make "microfluidic" devices for rapid medical diagnostics and chemical analysis.

New lab-on-chip advance uses low-cost, disposable paper strips

West Lafayette, IN | Posted on January 26th, 2011

The innovation represents a way to enhance commercially available diagnostic devices that use paper-strip assays like those that test for diabetes and pregnancy.

"With current systems that use paper test strips you can measure things like pH or blood sugar, but you can't perform more complex chemical assays," said Babak Ziaie, a Purdue University professor of electrical and computer engineering and biomedical engineering. "This new approach offers the potential to extend the inexpensive paper-based systems so that they are able to do more complicated multiple analyses on the same piece of paper. It's a generic platform that can be used for a variety of applications."

Findings are detailed in a research paper published online this week in the journal Lab on a Chip.

Current lab-on-a-chip technology is relatively expensive because chips must be specifically designed to perform certain types of chemical analyses, with channels created in glass or plastic and tiny pumps and valves directing the flow of fluids for testing.

The chips are being used for various applications in medicine and research, measuring specific types of cells and molecules in a patient's blood, monitoring microorganisms in the environment and in foods, and separating biological molecules for laboratory analyses. But the chips, which are roughly palm-size or smaller, are difficult to design and manufacture.

The new technique is simpler because the testing platform will be contained on a disposable paper strip containing patterns created by a laser. The researchers start with paper having a hydrophobic - or water-repellant - coating, such as parchment paper or wax paper used for cooking.

"We can buy this paper at any large discount retail store," Ziaie said. "These patterns can be churned out in the millions at very low cost."

A laser is used to burn off the hydrophobic coatings in lines, dots and patterns, exposing the underlying water-absorbing paper only where the patterns are formed.

"Since the hydrophobic agent is already present throughout the thickness of the paper, our method creates islands of hydrophilic patterns," Ziaie said. "This modified surface has a highly porous structure, which helps to trap and localize chemical and biological aqueous reagents for analysis. Furthermore, we've selectively deposited silica microparticles on patterned areas to allow diffusion from one end of a channel to the other."

Those microparticles help to wick liquid to a location where it would combine with another chemical, called a reactant, causing it to change colors and indicating a positive or negative test result.

Having a patterned hydrophilic surface is needed for many detection methods in biochemistry, such as enzyme-linked immunosorbent assay, or ELISA, used in immunology to detect the presence of an antibody or an antigen in a sample, Ziaie said.

To demonstrate the new concept, the researchers created paper strips containing arrays of dots dipped in luminol, a chemical that turns fluorescent blue when exposed to blood.

"Then we sprayed blood on the strips, showing the presence of hemoglobin," said Ziaie, whose research is based at the Birck Nanotechnology Center in the university's Discovery Park. "This is just a proof of concept."

Laser modification is known to alter the "wettability" of materials by causing structural and chemical changes to surfaces. However, this treatment has never before been done on paper, he said.

The researchers performed high-resolution imaging and spectroscopic analysis to study the mechanism behind the hydrophobic-hydrophilic conversion of laser-treated parchment paper.

The new approach is within a research area called paper microfluidics.

"Other techniques in paper microfluidics are more complicated," Ziaie said.

For example, other researchers have developed a method that lays down lines of wax or other hydrophobic material on top of untreated, hydrophilic paper.

"Our process is much easier because we just use a laser to create patterns on paper you can purchase commercially and it is already impregnated with hydrophobic material," Ziaie said. "It's a one-step process that could be used to manufacture an inexpensive diagnostic tool for the developing world where people can't afford more expensive analytical technologies."

The strips might be treated with chemicals that cause color changes when exposed to a liquid sample, with different portions of the pattern revealing specific details about the content of the sample. One strip could be used to conduct dozens of tests, he said.

The strips might be inserted into an electronic reader, similar to technology used in conventional glucose testers. Color changes would indicate the presence or absence of specific chemical compounds.

The research paper was written by graduate students Girish Chitnis, Zhenwen Ding and Chun-Li Chang; Cagri A. Savran, an associate professor of mechanical engineering, biomedical engineering and electrical and computer engineering; and Ziaie.

The National Science Foundation funded the work.

The researchers have patented the technique and it is available for licensing through Joseph Trebley, senior project manager for the Purdue Research Foundation Office of Technology Commercialization, at 765-588-3832, (www.prf.org/otc).

ABSTRACT

Laser-treated Hydrophobic Paper: An Inexpensive Microfluidic Platform


Girish Chitnis1,5, Zhenwen Ding2,5, Chun-Li Chang1,5, Cagri A. Savran1,3,4,5 and Babak Ziaie3,4,5,a)

1School of Mechanical Engineering, Purdue University

2Department of Physics, Purdue University, West Lafayette

3School of Electrical and Computer Engineering

4Weldon School of Biomedical Engineering, Purdue University

5Birck Nanotechnology Center, Purdue University


We report a method for fabricating inexpensive microfluidic platforms on paper using laser treatment. Any paper with a hydrophobic surface coating (e.g., parchment paper, wax paper, palette paper) can be used for this purpose. We were able to selectively modify the surface structure and property (hydrophobic to hydrophilic) of several such papers using a CO2 laser. We created patterns down to a minimum feature size of 62±1µm. The modified surface exhibited a highly porous structure which helped to trap/localize chemical and biological aqueous reagents for analysis. The treated surfaces were stable over time and were used to self-assemble arrays of aqueous droplets. Furthermore, we selectively deposited silica microparticles on patterned areas to allow lateral diffusion from one end of a channel to the other. Finally, we demonstrated the applicability of this platform to perform chemical reactions using luminol-based hemoglobin detection.

####

For more information, please click here

Contacts:
Writer:
Emil Venere
765-494-4709


Source:
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

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Microfluidics/Nanofluidics

Fabrication of a Miniature Paper-Based Electroosmotic Actuator November 29th, 2016

Researchers use acoustic waves to move fluids at the nanoscale November 15th, 2016

Researchers use temperature to control droplet movement: Method for moving fluids on a surface may find uses in condensers, microfluidics, and de-icing October 14th, 2016

Novel nanoscale detection of real-time DNA amplification holds promise for diagnostics: Research team led by Nagoya University develop a label-free method for detecting DNA amplification in real time based on refractive index changes in diffracted light September 12th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Construction of practical quantum computers radically simplified: Scientists invent ground-breaking new method that puts quantum computers within reach December 5th, 2016

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

Research Study: MetaSOLTM Shatters Solar Panel Efficiency Forecasts with Innovative New Coating: Coating Provides 1.2 Percent Absolute Enhancement to Triple Junction Solar Cells December 2nd, 2016

Possible Futures

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Fast, efficient sperm tails inspire nanobiotechnology December 5th, 2016

Construction of practical quantum computers radically simplified: Scientists invent ground-breaking new method that puts quantum computers within reach December 5th, 2016

Academic/Education

Oxford Nanoimaging report on how the Nanoimager, a desktop microscope delivering single molecule, super-resolution performance, is being applied at the MRC Centre for Molecular Bacteriology & Infection November 22nd, 2016

The University of Applied Sciences in Upper Austria uses Deben tensile stages as an integral part of their computed tomography research and testing facility October 18th, 2016

Enterprise In Space Partners with Sketchfab and 3D Hubs for NewSpace Education October 13th, 2016

New Agricultural Research Center Debuts at UCF October 12th, 2016

Nanomedicine

Fast, efficient sperm tails inspire nanobiotechnology December 5th, 2016

Journal Nanotechnology Progress International (JONPI) Volume 6, issue 2 coming out soon! December 5th, 2016

UTSA study describes new minimally invasive device to treat cancer and other illnesses: Medicine diffusion capsule could locally treat multiple ailments and diseases over several weeks December 3rd, 2016

Nanobiotix Provides Update on Global Development of Lead Product NBTXR3: Seven clinical trials across the world: More than 2/3 of STS patients recruited in the “act.in.sarc” Phase II/III trial: Phase I/II prostate cancer trial now recruiting in the U.S. November 28th, 2016

Announcements

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Nanobiotechnology

Fast, efficient sperm tails inspire nanobiotechnology December 5th, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Nanobiotix Provides Update on Global Development of Lead Product NBTXR3: Seven clinical trials across the world: More than 2/3 of STS patients recruited in the “act.in.sarc” Phase II/III trial: Phase I/II prostate cancer trial now recruiting in the U.S. November 28th, 2016

From champagne bubbles, dance parties and disease to new nanomaterials: Understanding nucleation of protein filaments might help with Alzheimer's Disease and type 2 Diabetes November 24th, 2016

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