March 12, 2012

Texas Researchers Develop Low-Cost, Easy To Use HIV, Malaria Test

Chemists from the University of Texas at Austin have developed a new origami-inspired paper sensor that can reportedly test for malaria, HIV, and other diseases and costs less than a dime per unit.

According to Gizmag reporter Ben Coxworth, the device is known as the origami Paper Analytical Device (oPAD) and was invented by university researchers Hong Liu and Richard Crooks. The oPAD is folded together by the user and was inspired by both the traditional Japanese art of paper folding and an earlier paper by Harvard chemist George Whitesides describing a three-dimensional microfluidic paper-bodied biosensor.

"Whitesides' device, however, required multiple pieces of paper to be patterned using photolithography, cut with lasers, then stuck together with two-sided tape. This somewhat complex production process would presumably be reflected in its price, and would require that it be assembled by trained personnel," Coxworth added. "Liu remembered being taught origami as a child in China, and wondered if a similar sensor could be created from a single sheet of paper, shipped flat, then folded into shape on-site."

Sure enough, he was successful after just a few weeks of experiment. The end product was a sensor, placed on a single sheet of paper using either photolithography or an office printer, than takes less than a minute to fold it into multiple layers and requires no additional tools to operate, the University said in a press release.

"Anybody can fold them up," Crooks said in a statement. "You don´t need a specialist, so you could easily imagine an NGO with some volunteers folding these things up and passing them out. They´re easy to produce, so the production could be shifted to the clientele as well. They don´t need to be made in the developed world."

The device has been successfully tested on both glucose and a protein, and is similar in nature to a home pregnancy test, he added. A hydrophobic material such as wax is placed into tiny canyons on chromatography paper, directing the substance being tested (such as urine, blood, or saliva) to areas on the paper where test reagents have been embedded, the university said.

"If the sample has whatever targets the sensor is designed to detect, it´ll react in an easily detectable manner. It might turn a specific color, for instance, or fluoresce under a UV light. Then it can be read by eye," they added.

Their findings, which were published last October in the Journal of the American Chemical Society and also appeared in last week's edition of Analytical Chemistry, could help provide new low-cost testing options for developing countries where other forms of testing could be too costly or difficult to use.

“This is about medicine for everybody,” Crooks said. "Biomarkers for all kinds of diseases already exist“¦ Basically you spot-test reagents for these markers on these paper fluidics“¦ Then you introduce your sample. At the end you unfold this piece of paper, and if it´s one color, you´ve got a problem, and if not, then you´re probably OK.”


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