Abstract: A multi-layered laminated test strip detector for formaldehyde is described which simplifies significantly the qualitative detection and quantitative determination of formaldehyde in aqueous solution or on the surface of wet solids. Layers of water soluble polymer are used to separate chemical reagents that otherwise will not be stable, and/or encapsulate the chemical reagents on bibulous material. Introducing the sample or wetting the detector through holes in a laminated encapsulating envelope permits the aqueous sample to dissolve the solid barrier when the sample is introduced and contact the reagents and the analyte, thereby forming color on the back side of the detector.