Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Rapid Test Uses Origami Technology

New concept for paper biosensors

Complex laboratory investigations do produce reliable results, but they are not useful for point-of-care diagnostics. This is especially true in developing countries, which must rely on simple, inexpensive test methods that do not require a power source.

Biosensors based on paper are an interesting alternative. American researchers from the University of Texas at Austin and the University of Illinois at Urbana-Champaign have now introduced a particularly clever concept in the journal Angewandte Chemie: print on one side of the paper, fold it up origami-style, laminate it, and the test is ready. Test evaluation requires only a voltmeter.

The team of researchers uses chromatography paper fabricated by wax printing. The printed areas become hydrophobic, while the unprinted paper remains hydrophilic. On one half of the paper, the researchers led by Richard M. Crooks and Hong Liu created a sample inlet and two hydrophilic channels, each leading from the inlet to a small chamber.

The two chambers are connected to each other through a narrow opening. The required reagents are also “printed” onto the paper. On the second half of the paper, a screen-printing process is used to add two electrodes made of conductive carbon ink. When the paper is then folded down the middle according to the principles of origami—no tape or glue—a three-dimensional structure is formed. This causes the electrodes to come into contact with the chambers. Finally, the folded paper is laminated.

When a drop of the sample is put into the inlet, the liquid moves through the two channels. One of the channels contains microspheres coated with an aptamer. An aptamer is a strand of DNA that can be constructed so as to selectively bind nearly any desired analyte molecule. For the purpose of demonstration, the researchers chose an aptamer for adenosine. If adenosine is in the sample, the aptamer binds to it. This releases an enzyme that was coupled to the aptamer. The enzyme continues to flow through the channel and reaches the chamber, which contains glucose and Prussian blue (iron hexacyanoferrate).

This complex contains trivalent iron. The enzyme, glucose oxidase, oxidizes the glucose, which causes the iron in the Prussian blue to be reduced to the divalent form.

The second channel contains spheres with no aptamer. In the second chamber, therefore, no iron is reduced. Because the oxidation state of the iron in one chamber has been changed, the two chambers no longer have the same composition and an electric potential builds up. This can be measured by means of a capacitor and a measuring device like those used to test the voltage of a battery.

This principle can be used to easily and inexpensively produce rapid tests for a broad spectrum of different target molecules.

About the Author
Dr. Richard Crooks is the Robert A. Welch Chair of Materials Chemistry at the University of Texas at Austin. He is interested in designing inexpensive diagnostic devices and in the field of electrochemical catalysis.
Author: Richard M. Crooks, The University of Texas at Austin (USA),
Title: Aptamer-Based Origami Paper Analytical Device for Electrochemical Detection of Adenosine

Angewandte Chemie International Edition, Permalink to the article:

Dr. Richard Crooks | Angewandte Chemie
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>