Researchers at National Taiwan University have developed a fast, low-cost paper-based test to detect hidden immune defects that make patients prone to severe, persistent infections. The device targets harmful autoantibodies that block interferon-gamma, a key immune molecule, leaving patients vulnerable to difficult-to-diagnose diseases. The study is published in Biosensors and Bioelectronics.

The test features a 3D folded paper structure integrated with gold nanoparticle signal amplification. All required reagents are preloaded in layered compartments, enabling the assay to start automatically when just a small drop of diluted blood serum is added—delivering results in only 10 minutes.

This one-step design not only streamlines the process but also improves sensitivity tenfold compared to conventional methods, detecting even trace levels of these autoantibodies in the early stages of illness.