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

AbstractA novel surface enhanced Raman spectroscopy (SERS) substrate was successfully fabricated on a silicon (Si) wafer using a 400nm inkjet printed thin film of silver (Ag) nanoparticle ink, with 150nm 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

Novel Fully Screen Printed Flexible Electrochemical Sensor For the Investigation of Electron Transfer between Thiol Functionalized Viologen and Gold Clusters

A novel electrochemical sensor was fabricated for the investigation of the effect of electron transfer between glutathione (GS) protected gold nanoparticles (AuNPs) and a new C4-thiol functionalized viologen axle molecule (V2+-SH) on pseudorotaxane formation. The sensor was fully screen printed with silver (Ag) ink on a flexible polyethylene terephthalate (PET) substrate. Square wave voltammetry (SQWV) based response of the sensor toward V2+-SH in the presence of Au25 or 4 nm-Au demonstrated oneelectron transfer processes, based on 59 mV changes in peak potentials to more negative values. The response demonstrated the capability of the novel electrochemical sensor to be used for studying complex systems in volumes as small as 5-10 μL, with less sample preparation time. © 2012 Elsevier B.V. All rights reserved