Gravure printed surface enhanced Raman spectroscopy (SERS) substrates for detection of toxic heavy metal compounds

A novel flexible surface enhanced Raman spectroscopy (SERS) substrate was successfully fabricated by gravure printing a silver (Ag) nanoparticle ink, with a particle size of ~20-50 nm particle size, as a metallization layer on a flexible polyethylene terephthalate film (PET). The capability of the fabricated SERS substrate to be used as a sensor for detecting toxic heavy metal compounds, such as mercury sulfide (HgS) was demonstrated. An enhancement factor of 5 orders of magnitude was obtained when compared to the intensity of a Raman spectrum of for target molecules adsorbed onto bare PET. Theis response obtained demonstrated the feasibility of thise novel SERS substrate to be used in applications for the detection of toxic heavy metals. In addition, the effect of temperature on the intensity of the Raman spectrum was also tested. The results showed an 85 % decrease in intensity at 85 °C, when compared with the intensity of te Raman sprectrum at 25 °C.