A Novel Inkjet Printed Surface Enhanced Raman Spectroscopy (SERS) Substrate for the Detection of Toxic Heavy Metals

A novel surface enhanced Raman spectroscopy (SERS) substrate was successfully fabricated on a silicon (Si) wafer using a 400 nm inkjet printed thin film of silver (Ag) nanoparticle ink, with 150 nm particle size. The capability of the fabricated SERS substrate for detecting toxic heavy metals such as mercury sulfide (HgS), cadmium sulfide (CdS) and zinc oxide (ZnO) was demonstrated. The SERS based response of the printed substrate produced an enhanced Raman signal when compared to that of target molecules adsorbed on bare Si wafer. An amplification of the SERS intensity by an order of 3 to 5 times was observed for all test samples, due to the presence of hotspots between the metal nanoparticle aggregates. The responses demonstrated the feasibility of the novel SERS substrate to be used in applications for detection of toxic heavy metals.