In anionic micelles, SDS has been found to remove the kinetic barrier for the reaction between methylene blue (MB) and arsine. The color bleaching (reduction) of SDS micelle bound MB by arsine gives a quantitative measure of arsenic concentration in the sub-parts-per-million levels for a test sample. Arsine is generated by reacting NaBH4 with arsenic-containing samples present along with the other reagents. The extent of the micelle-bound dye reduction is facilitated in the presence of Ag or Au nanoparticles. The micelles, in turn, help to increase the collision probability between the dye and arsine, whereas nanoparticles help the electron relay from AsH3 to the micelle-bound dye. This method depicts for the first time a simple, reproducible way to demonstrate nanoparticle-catalyzed dye reduction by arsine in an organized medium.