Detection of multiple explosives by surface enhanced Raman scattering

  • Kirsty Milligan

Student thesis: Doctoral Thesis

Abstract

Military grade explosives such as 2,4,6-trinitroluene (TNT) are still a major worldwide concern in terms of terror threat and environmental impact. The most common methods currently employed for the detection of explosives involve colourimetric tests, which are known to be rapid and portable, however often display false positives and lack sensitivity. Other methods used include ion mobility mass spectrometry, gas chromatography – mass spectrometry (GC-MS) and liquid chromatography – mass spectrometry (LC-MS), which despite producing more reliable results; require large, expensive instrumentation and specially trained staff. This main aim of this research was to develop a novel method of explosives detection which had the capability of detecting multiple explosive compounds simultaneously in a robust, quick and sensitive assay format, which was easily translatable for use in the field. Initially, this research focussed on commercially available SERS substrates as a method of detection for the nitroaromatic explosives TNT, tetryl and HNS. The major disadvantage of this method of detection was the sensitivity, reproducibility and cost of the SERS substrates making them unsuitable for the detection of low levels of analyte. This led to the investigation of SERS detection using silver nanoparticles combined with modification of the explosives TNT, tetryl and HNS into SERRS active species for the development of a more selective and readily translatable solution based method of detection. Furthermore, TNT could be positively identified in samples which contained various interferents and contaminants which is representative of “real world” samples.Finally, the use of aptamers and molecular beacons was investigated as a means of qualitative detection of the illicit drug, methamphetamine and single stranded DNA sequences which code for disease. Methamphetamine was chosen as the target for proof-of-concept work in which aptamers could be used for the detection of small molecules, namely drugs and explosives using an “off” to “on” molecular beacon approach combined with SERS.
Date of Award19 Sep 2019
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SponsorsEPSRC (Engineering and Physical Sciences Research Council)
SupervisorKaren Faulds (Supervisor) & Duncan Graham (Supervisor)

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