A colorimetric agarose gel for formaldehyde measurement based on nanotechnology involving Tollens reaction

Gold nanoparticles (Au NPs) coupled with Tollens reagent were used for measuring formaldehyde. Au@Ag core–shell NPs were formed along with distinct color changes from pink to deep yellow. This colorimetric system was further immobilized into an agarose gel, which was used for monitoring of gaseous formaldehyde.