Device improves sensitivity and effectiveness of point-of-care tests

Point-of-care tests are used by physicians and patients for quick and reliable testing and diagnosis. Unfortunately, their sensitivity is often limited when working with diluted analytes, and accuracy needs to be improved. Drexelius et al. developed a high-pressure preconcentration device to increase the amount of target analyte in a sample, improving sensitivity and accuracy.

“Our device is capable of using saliva, a biofluid sample that is much easier to obtain and much more comfortable for the patient in comparison to the nasopharyngeal swab, which is the current standard for respiratory viruses,” said author Amy Drexelius.

The device works by harnessing pressure gradients to push water and interferents through a membrane filter, which concentrates the analytes in the sample. It is rapid (preconcentrating the analytes in as little as 5 minutes), mobile and inexpensive to create.

“Ideally, high risk patients would be able to use the device with a point-of-care assay to test a saliva sample every few days in their own home during flu season,” said Drexelius. “The patient would know that they have the flu before they are showing symptoms and could then get to the doctor to obtain an antiviral in the virus’ early stages, when the medication would be more effective.”

Future improvements on the device will include adapting it, so one device can be used for multiple analytes of varying size. The authors hope to add a small scale to the waste reservoir of the device to improve the predictability of preconcentration.

Source: “Analysis of pressure-driven membrane preconcentration for point-of-care assays,” by A. Drexelius, A. Hoellrich, A. Jajack, E. Gomez, M. Brothers, S. Hussain, S. Kim, and J. Heikenfeld, Biomicrofluidics (2020). The article can be accessed at https://doi.org/10.1063/5.0013987 .