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dc.contributor.authorWilson, Nicholasen
dc.date.accessioned2020-06-03T19:45:22Z
dc.date.available2020-06-03T19:45:22Z
dc.identifier.urihttp://hdl.handle.net/1974/27887
dc.description.abstractSurface-enhanced Raman scattering (SERS) is an analytical technique that can provide ultra-sensitive chemical detection on a mobile platform when implemented on handheld Raman spectrometers. However, the large laser spot size of handheld Raman spectrometers requires SERS substrates of sufficient surface area. In this work, we present a straightforward method of fabricating silver nanostructured SERS substrates, and subsequently demonstrate the substrates’ viability as drug checking tools to help combat the opioid crisis. We first demonstrate that electrochemically reducing silver ions onto silicon-gold microchips from a large `bath’ of aqueous solution results in highly-branched, nanostructured films that grow laterally across the silicon surface. The process is found to decrease production time and improve batch-to-batch reproducibility when compared to the existing 'droplet' protocol, which uses a smaller volume of reagent solution. In addition, we study the effect of temperature and mass transfer on lateral nanostructure growth with the intent of achieving large surface area substrates for use with handheld Raman spectrometers. While neither of these factors is found to have a significant effect on the extent of nanostructure growth, the study confirms that the nanostructured films grow under a mass transfer-controlled regime. We finally hypothesize that lateral growth is limited by electrical impedance within the nanostructure. We subsequently establish our SERS substrates’ viability as a drug checking tool, specifically for the detection of fentanyl in drugs. We determine fentanyl’s limit of detection on our platform as 0.078 ppm. SERS spectra of fentanyl, furanylfentanyl, and carfentanil are classified using multivariate analysis coupled with machine classification models. The classification model also identifies trace fentanyl amidst high concentrations of heroin and caffeine. Finally, we achieve SERS fentanyl detection using a handheld Raman device, thus setting a precedent for point-of-care drug checking.en
dc.language.isoengen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsQueen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canadaen
dc.rightsProQuest PhD and Master's Theses International Dissemination Agreementen
dc.rightsIntellectual Property Guidelines at Queen's Universityen
dc.rightsCopying and Preserving Your Thesisen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectSERSen
dc.subjectSensorsen
dc.subjectNanomaterialsen
dc.subjectFentanylen
dc.subjectHarm Reductionen
dc.subjectDrug Checkingen
dc.subjectMultivariate Analysisen
dc.subjectMachine Classificationen
dc.subjectOpioid Crisisen
dc.subjectPoint-of-care Deviceen
dc.titleElectrodeposited Surface-Enhanced Raman Scattering Substrates for Point-of-Care Drug Checkingen
dc.typethesisen
dc.description.degreeM.A.Sc.en
dc.contributor.supervisorDocoslis, Aristides
dc.contributor.departmentChemical Engineeringen
dc.degree.grantorQueen's University at Kingstonen


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