Methods and materials for the detection of melamine in test samples such as foodstuffs are described. Embodiments of the invention comprise combining a test sample suspected of containing melamine with a particle that produces a colorimetric and/or turbidimetric signal that is dependent upon the concentration of melamine in the test sample. In certain embodiments of the invention, the particles and test sample are combined together with a chemical compound selected to induce the aggregation melamine in a manner that amplifies the colorimetric and/or turbidimetric signal of the assay. In some embodiments of the invention, the aggregation inducing agent is not physically coupled to the particles used in the assays. In other embodiments of the invention, the aggregation inducing agent is physically coupled to the particles used in these assays.