Surface-enhanced Raman scattering (SERS), a variant of Raman spectroscopy, is a powerful analytical technique that exploits plasmonics to obtain detailed chemical information of molecules or molecular assemblies adsorbed or attached to nanostructured metallic surfaces. In this work, we have presented a design of easy to fabricate, flexible and cost-effective SERS substrate constituting of chemically synthesized Ag nanoparticles (particle size of 10-15 nm) embedded superficially on hot-melt adhesive (bio-grade quality) commonly referred as glue stick and used as adhesive. The laser source with λ=785nm is irradiated on the substrate on which the sample to be identified/analyzed is drop-cast, here we have used Rhodamine 6G (R6G) (sigma Aldrich) as probe molecule. The resonant wavelength of Ag NPs was determined using UV-Visible spectroscopy and was found out to be ~ 408 nm. SERS can be used to identify an unknown analyte (provided it should be Raman active) on the basis of its Raman signature. We have demonstrated the detection of R6G (20μL) upto10-4 M (~4.8 ppm) concentration on our in-house Raman setup using this SERS substrate. This set-up can be easily used to detect/identify different analytes at much lower concentrations. All Raman peaks of R6G were distinctively visible for analysis. We can use this SERS substrate for on-site narcoanalysis, forensic study, explosive detection, bio-diagnostics, detection of adulterants in food/water etc. using portable Raman spectrometer for rapid analysis, with no sample preparation time.
|