Paper-Based Flexible Nanoparticle Hybrid Substrate for Qualitative and Quantitative Analysis of Melamine in Powder...

Melamine is a chemical compound that is added to dairy products to increase the apparent protein content for higher profit margins. However, extended consumption of melamine can cause health risks. The SERS technique has proven to be an important tool for detecting small compounds, such as melamine. Here, a paper-based flexible nanoparticles (NPs)-hybrid SERS substrate was designed by drop-casting pegylated gold nanoparticles (AuNPs) on the filter papers. In SERS characterization, this substrate exhibited an enhancement factor of 10⁸ and a limit of detection (LOD) as low as 10^-8 M for Rhodamine 6G dye. Furthermore, we successfully utilized these substrates to detect the melamine spiked milk sample with an LOD as low as 0.01 ppm. This hybrid SERS substrate offers a low-cost, biocompatible, and easy-to-use fabrication for large-scale production, which may be widely used in food safety applications.