Applications of functional materials in the analysis of aqueous samples

Abstract

In chapter 1, a solid phase extraction method which allowed for enhanced qPCR output when detecting COVID-19 mRNA from complex wastewater streams across different wastewater treatment sites in Northern Ireland was developed.
This work took two parallel research streams, in the first, a range of commercial and bespoke polymeric extractant materials, chosen for their range of functionalities, pore sizes and hydrophilicities were prepared, packed into SPE cartridges, and integrated into a qPCR workflow. The improvement in qPCR signal elicited by each treatment method was then monitored. In the second, a general characterization of contaminants found within wastewater in Northern Ireland was undertaken using IC and GCMS. In this research stream, the contamination profile of wastewater from each tested site was compared before and after SPE treatment. Combination of both research streams allowed an iterative design approach to be undertaken. Successful candidate polymers were in some cases capable of eliciting improvements in qPCR intensity as high as 300%, and scale-up of these polymers synthesis was undertaken.

In chapter 2, a combined MISPE-SERS (molecular imprinted solid phase extraction – surface enhanced Raman scattering) method for the selective detection of a range of carboxylate containing compounds is designed and evaluated. This chapter outlines methods used for:
• validating interactions between functional monomers and analytical targets.
• polymer synthesis, characterization, and performance validation.
• Colloidal nanoparticle aggregation, nanoparticle self-assembly and SERS
detection.
• SPE method development and terminal detection using SERS.
This work in this chapter allowed for completion of a MISPE-SERS detection method for benzoic acid and partial completion of a MISPE-SERS detection method for 2,4-dichlorophenoxy acetic acid, using a dummy imprinting approach.

In chapter 3, a new method for the ‘stamping’ of a monolayer of metal nanoparticles into a robust polypropylene backbone to produce surface exposed nanosheets of greater chemical, physical and thermal robustness is outlined.

Thesis is embargoed until 31st December 2026.

Date of Award	Dec 2023
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	Northern Ireland Department for the Economy
Supervisor	Steven Bell (Supervisor) & Panagiotis Manesiotis (Supervisor)