Traffic light type paper-based analytical device for intuitive and semi-quantitative naked-eye signal readout.

Abstract in brief

• The article describes a paper-based device designed for quick, easy, and semi-quantitative detection of substances in a sample, which displays results as traffic light colors (green, yellow, red) to indicate different concentration levels without the need for instruments or calculations.
• The device functions by controlling how the sample flows through paper channels that change based on the concentration of hydrogen peroxide, enabling users to interpret the results visually and simply by color change after about 10–30 minutes.
• Demonstrated with glucose detection in artificial urine, this platform aims to meet clinical testing standards, offering a straightforward way to detect various metabolites in point-of-care settings, with potential for future expansion to other biological markers.]