Enhanced Raman intensity of pollutants and explosives by using 2-mercaptoethanol controlled pyramid Ag–iron nanostructure embedded graphene oxide platform

•Detection of TNT by using SERS with pyramid Ag–Fe nanostructure on GO.•R6 G dye detected better by SERS with elliptical Ag nanostructures on GO layers.•Annealed pyramid Ag–Fe nanostructure on GO detected TNT and pyrene by SERS.•Annealed pyramid Ag–Fe nanostructure on GO detected R6G down to micromolar level.•Improved substrate developed for SERS. In this study, a pyramid Ag–Fe embedded graphene oxide nanocomposite (PAFG) was synthesized and characterized using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and ultraviolet–visible (UV-V–visible (UV–vis) spectroscopy. FESEM images indicated the successful synthesis of exfoliated graphene sheets with a thickness of 7 nm, 30 nm Fe nanoparticles, and pyramid Ag nanostructures, where the sides measured from 100 nm to 600 nm. UV–vis analysis detected plasmon bands at 700 nm and 914 nm for PAFG. EDS analysis confirmed the presence of elemental Ag and C. Two PAFG phases were obtained after centrifugation, which were designated as PAFG1 and PAFG2. Surface enhanced Raman spectroscopy (SERS) analyses showed that the rhodamine 6G (R6G) peaks with PAFG1 were 1.75 times larger than those with trinitrotoluene (TNT) and 1.7 times larger than those with pyrene. SERS analysis of TNT with PAFG2 obtained 1.49 and 1.3 times greater peaks compared with those using pyrene and R6G, respectively. On average, the performance was around 1.4 times better with PAFG2 for each of the analytes. Measurements of the SERS spectra for TNT and pyrene with annealed PAFG (at mM and μM concentrations) showed that the enhancement factors (EFs) were 2.2 and 1.7 for the μM TNT and pyrene samples, respectively. Comparisons of the SERS spectra obtained for mM samples of the three analytes with annealed PAFG showed that the EFs were over three times higher than that with R6G.