Multi-Target Paper Diagnostic Test Offers New Applications

The diagnosis of a disease is a crucial first step in the delivery of care. However, many parts of the world do not have the centralized infrastructure and trained personnel to perform these tests. This leads to the need for low-cost test solutions that can be delivered at the point of care. To meet this demand, easy-to-read paper diagnostic tests have been developed and implemented to combat a number of diseases worldwide, creating a market of nearly $ 6 billion. These paper tests, commonly referred to as lateral flow tests, detect the presence of specific molecules in a sample, such as blood or urine, by inducing a color change along a "test line." "located on the paper strip, functioning similarly to the well. known pregnancy tests.

Although such paper tests have been developed to detect a number of disease-causing agents such as malaria parasites, HIV, and Zika virus, they can not detect multiple types of molecules simultaneously, which limits their application to a wider range of diagnostic needs.

Researchers at UCLA's Samueli School of Engineering have created a new paper-based sensor that overcomes these limitations, paving the way for new diagnostic applications. The results of the evaluation of this new low-cost paper-based sensor have been published in Lab on a chip, Journal of the Royal Society of Chemistry (United Kingdom).

Aydogan Ozcan, Professor Chancellor of Electrical and Computer Engineering and Associate Director of the California NanoSystems Institute at UCLA led the research in collaboration with Professor Dino Di Carlo of UCLA's Bioengineering Department, Professor Omai Garner, Director Associate of the UCLA Clinical Microbiology Laboratory, and Dr. Hyou-Arm Joung, Senior Research Associate in the Department of Electrical and Computer Engineering of UCLA.

This new paper-based sensor uses a specially designed "sensing membrane" that contains dozens of individual reaction points, each of which can detect a specific molecule for a different disease. This operation is made possible by the placement of a vertical stack of layers of paper and wax, carefully developed so that the sample of the patient, in this case the treated blood, interact uniformly with each reaction point on the paper of 1 cm x 1 cm. detection membrane based. Therefore, this multi-sensing design can perform much more complex tests needed for, for example, cancer, cardiovascular disease or Lyme disease, among others, while using paper media with a value of 0 , $ 30, as well as simple steps that can be done in less than 20 years. minutes with minimal training of the user.

It is important to note that the UCLA team has also developed a low-cost mobile phone attachment, which is used to badyze paper tests, quickly reporting the results to the user via a mobile app .

"This new multiplexed test platform promises to propel paper diagnostics into exciting new territories, as it can be adapted to different diagnostic targets," said Dr. Ozcan. "In fact, we have already found a promising opportunity for the diagnosis of Lyme disease with our multiplexed paper-based sensor."

The researchers tested the performance of the new paper-based sensor on human blood serum samples that were found to be positive for Lyme disease, demonstrating the simultaneous detection of three common Lyme disease-specific antibodies, which seems promising as a future diagnostic tool that can replace expensive equipment. and trained technicians currently needed to perform traditional laboratory tests. As Lyme disease becomes more and more prevalent in the United States, Ozcan's recent invention and colleagues is an important step in the fight against this growing threat to public health.

Provided by
UCLA Engineering Institute for Technology Advancement