Development of cost-effective fabrication process for on-site methamphetamine detection by adsorbable SERS substrate

In this study, the adsorbable SERS substrate was successfully fabricated on polydimethylsiloxane (PDMS) with the nanometer-sized roughness existing in a micrometer-sized roughness (nano-in-micro rough) structure which was completely transferred from the laser engraving aluminum (Al) mold by a replication process. Then the silver nanoparticle (Ag NPs) was deposited by magnetron sputtering. The physical morphology of the obtained samples was characterized by a field emission scanning electron microscope (FE-SEM). The ability for direct adsorb trace detection of the methylene blue (MB) on the glass slide surface was investigated. From the results, the SERS signal of the prepared adsorbable SERS substrates was influenced by the topography of the nano-in-micro rough feature and Ag NPs. It was found that combined nano-in-micro rough and microgroove structures exhibit high sensitivity of MB (10−5 M). In addition, the optimum adsorbable SERS substrate was then applied in practical application by adsorbing the methamphetamine (MAP) residues on the glass slide surface with a limit of 10−2 M, which could be expected to be an on-site screening platform for drugs detection.