Portable diagnostic tool detects disease in 15 minutes

By inkjet-printing an array of antibodies onto a glass slide with a non-stick polymer coating, the D4 assay diagnostic tool from Duke University is a self-contained test that detects low levels of antigens - the protein markers of a disease - from a single drop of blood.

By creating a sensitive, easy-to-use "lab on a chip," the researchers plan to bring rapid diagnostic testing to areas that lack access to standard lab-based diagnostic technologies. The platform is described in the Proceedings of the National Academy of Sciences.

The current gold standard for quantitative diagnostic tests is the enzyme-linked immunosorbent assay (ELISA), which identifies how many specific antigens are present in a biological sample.

The D4 assay reportedly allows clinicians to avoid problems associated with ELISA – such as ease of use, time taken for diagnosis, and bulky lab instruments - without sacrificing sensitivity or accuracy.

The new assay can quickly identify a disease biomarker, and results can be read using a tabletop scanner or 3D printed smartphone attachment that uses the phone's camera to read the results.